The Israeli government on Thursday urged its citizens to avoid travel to the United Arab Emirates and Bahrain, citing threats of Iranian attacks.

Iran has been threatening to attack Israeli targets since its chief nuclear scientist, Mohsen Fakhrizadeh, was assassinated last Friday near Tehran. It accuses Israel, which has been suspected in previous killings of Iranian nuclear scientists, of being behind the shooting, reports AP.

Israel has not commented on the killing. But Fakhrizadeh has long been on Israel’s radar screen, with Prime Minister Benjamin Netanyahu saying at a 2018 news conference about Iran’s nuclear program: “Remember that name.” Israel accuses Iran of trying to develop nuclear weapons — a charge Iran denies.

In recent months, Israel has signed agreements establishing diplomatic relations with Gulf Arab states of the UAE and Bahrain — its first normalization deals with Arab countries in a quarter century.

The agreements, brokered by the Trump administration, have generated widespread excitement in Israel, and thousands of Israeli tourists are scheduled to travel to the UAE for the Jewish holiday of Hanukkah this month.

That may change following Thursday’s warning.

“In light of the threats heard recently by Iranian officials and in light of the involvement in the past of Iranian officials in terror attacks in various countries, there is a concern that Iran will try to act in this way against Israeli targets,” said a statement issued by the prime minister’s National Security Council.

It also advised against travel to Georgia, Azerbaijan, Turkey, the Kurdish area of Iraq and Africa.

Israel’s military is well prepared to deal with the threats of Iranian troops and their proxies in neighboring Syria, Lebanon and the Gaza Strip. Israeli media say the government also has beefed up security at embassies around the world.

But protecting Israeli travelers, conspicuous and spread out at countless hotels, restaurants and tourist sites, represents a different type of challenge.

“This is going to be a nightmare, and I really hope that both governments, UAE and Israel, are coordinating and doing the best they can to safeguard those Israelis,” said Yoel Guzansky, a former Israeli counterterrorism official who is now a senior fellow at the Institute for National Security Studies in Tel Aviv.

“I’m really worried that that something might happen, and especially now because of the context of Fakhrizadeh, because Iran is really looking for revenge,” he added. He spoke before the travel advisory was issued.

The Israel Airports Authority estimates that about 25,000 Israelis will fly to the UAE this month on the five airlines now plying the route between Tel Aviv and the Gulf state’s airports in Dubai and Abu Dhabi. Celebrities, entrepreneurs and tourists already have been flocking to Dubai.

With the coronavirus appearing to be under control in the UAE, it is one of the few quarantine-free travel options for Israelis during the coming Hanukkah holiday vacation, adding to its appeal. At a time when few people are traveling, Israeli visitors speaking Hebrew could be extra conspicuous.

Israel this week also signed a tourism agreement with Bahrain.

Amsalem Tours, an Israeli travel agency, said that there was “very serious” demand for travel packages to Dubai but did not provide specific figures.

Iran and its proxies have targeted Israeli tourists and Jewish communities in the past. Agents of the Lebanese militant Hezbollah group bombed a bus carrying Israeli tourists in Burgas, Bulgaria, in 2012, killing six and wounding dozens. That year, Israel also accused Iran of being behind attacks targeting Israeli diplomats in Thailand and India. Iran and Hezbollah also bombed the Israeli Embassy and Jewish community center in Buenos Aires in 1992 and 1994, claiming the lives of scores of civilians.

Concerns for the safety of Israelis in Dubai also is not without precedent. In 2000, an Israeli ex-colonel was kidnapped by Iranian proxy Hezbollah and held captive in Lebanon until he was released in a prisoner exchange in 2004.

Today, Dubai, famous for its glittering shopping malls, ultra-modern skyscrapers and nightlife, is a crossroads for travelers from around the world, including many nations that do not have relations with Israel. Iran maintains a major presence in Dubai, due to historical and current trade ties, and Dubai is believed to be a major station for Iranian intelligence services. The family of a California-based member of an Iranian militant opposition group in exile says he was abducted by Iran while staying in Dubai just a few months ago.

In a possible sign of Emirati security concerns, travel agencies in countries across the Middle East and Africa say the UAE has temporarily halted issuing new visas to their citizens. With tens of thousands of Iranians working or doing business in the UAE, Iran is also among the countries facing the visa restrictions.

Israel had already had a travel warning in place advising citizens against nonessential travel to the UAE. Similar “basic concrete threat” advisories are in place for visiting other Arab states with which Israel has peace treaties. But the language of Thursday’s warning was especially tough.

The UAE, for its part, is known for its strict security. Dubai, home to 3.3 million people in 2019, with just over 3 million of them foreigners, has published major crime statistics that are among some of the lowest in the world.

Before Israelis began arriving, Dubai held a highly publicized drill of a police SWAT team storming a replica metro car in October and suggested facial-recognition technology could be implemented at stations along its driverless track. Experts already believe the UAE has one of the highest per capita concentrations of surveillance cameras in the world, a system that’s only grown amid the coronavirus pandemic.

And despite the recent tensions, Iran may be hesitant to strike on Emirati soil, wanting to maintain its economic interests there. The UAE meanwhile has gone out of its way to say it wants to de-escalate tensions in the region despite its own suspicions over Iranian behavior. It called the killing of Fakhrizadeh a “heinous assassination.”

In an interview before Thursday’s advisory was issued, Pavel Israelsky, co-founder of Salam Dubai, said the boom in his UAE-based Israeli tour operator’s bookings was “significant” ahead of the Hanukkah holiday. While a handful of Israeli clients canceled over security concerns, he said, “I can say that the UAE is one of the most secure places in the world in terms of the resources they invest in security.”

“I don’t think there’s cause for worry,” Israelsky said. “Today, no place is really safe.”

Also read: Iran says Israel remotely killed military nuclear scientist

An opinion piece published Sunday by a hard-line Iranian newspaper urged Iran to attack the Israeli port city of Haifa if Israel carried out the killing of the scientist who founded the Islamic Republic’s military nuclear program in the early 2000s.

Though the hard-line Kayhan newspaper has long argued for aggressive retaliation for operations targeting Iran, Sunday’s opinion piece went further, suggesting any assault be carried out in a way that destroys facilities and “also causes heavy human casualties.”

Israel, suspected of killing Iranian nuclear scientists over the past decade, has not commented on the brazen slaying of Mohsen Fakhrizadeh. A military-style ambush Friday on the outskirts of Tehran reportedly saw a truck bomb explode and gunmen open fire on the scientist, killing him and a bodyguard, reports AP.

U.S. intelligence agencies and U.N. nuclear inspectors have said the organized military nuclear program that Fakhrizadeh oversaw disbanded in 2003, but Israeli suspicion of Tehran’s atomic program and his involvement has never ceased.

Kayhan published the piece written by Iranian analyst Sadollah Zarei, who argued Iran’s previous responses to suspected Israeli airstrikes that killed Revolutionary Guard forces in Syria did not go far enough to deter Israel. He said an assault on Haifa also needed to be greater than Iran’s ballistic missile attack against American troops in Iraq following the U.S. drone strike in Baghdad that killed a top Iranian general in January.

Striking the Israeli city of Haifa and killing a large number of people “will definitely lead to deterrence, because the United States and the Israeli regime and its agents are by no means ready to take part in a war and a military confrontation,” Zarei wrote.

While Kayhan is a small circulation newspaper in Iran, its editor-in-chief Hossein Shariatmadari was appointed by Supreme Leader Ayatollah Ali Khamenei and has been described as an adviser to him in the past.

Haifa, on the Mediterranean Sea, has been threatened in the past by both Iran and one of its proxies, the Lebanese militant group Hezbollah.

Such a strike likely would draw an immediate Israeli retaliation and spark a wider conflict across the Mideast. While Iran has never directly targeted an Israeli city militarily, it has conducted attacks targeting Israeli interests abroad in the past over the killing of its scientists, like in the case of the three Iranians recently freed in Thailand in exchange for a detained British-Australian academic.

Israel also is widely believed to have its own nuclear weapons, a stockpile it neither confirms nor denies possessing.

The Iranian parliament on Sunday held a closed-door hearing about Fakhrizadeh’s killing. Afterward, parliament speaker Mohammad Baqer Ghalibaf said Iran’s enemies must be made to regret killing him.

“The criminal enemy does not regret it except with a strong reaction,” he said in a broadcast on Iranian state radio.

A public session of lawmakers saw them chant: “Death to America!” and “Death to Israel!”

They also began the review of a bill that would stop inspections by the International Atomic Energy Agency. The nuclear watchdog has provided an unprecedented, real-time look at Iran’s civilian nuclear program following the country’s 2015 nuclear deal with world powers.

The deal has unraveled after Trump’s unilateral 2018 withdrawal of the U.S. from the accord. Iran’s civilian atomic program has since continued its experiments and now enriches a growing uranium stockpile up to 4.5% purity.

That’s still far below weapons-grade levels of 90%, though experts warn Iran now has enough low-enriched uranium to reprocess into fuel for at least two atomic bombs if it chose to pursue them. The proposed bill reportedly also would require Iran’s civilian atomic program to produce at least 120 kilograms (265 pounds) of uranium enriched to 20% — a short technical step to 90%.

Iran’s 290-seat parliament is dominated by hard-liners who likely would support the bill. It ultimately would have to be approved by Iran’s Guardian Council. Khamenei also has final say on all matters of state.

Khamenei has called Fakhrizadeh “the country’s prominent and distinguished nuclear and defensive scientist” and has demanded the “definitive punishment” of those behind the killing, without elaborating.

Fakhrizadeh headed Iran’s so-called AMAD program that Israel and the West have alleged was a military operation looking at the feasibility of building a nuclear weapon. The IAEA says the “structured program” ended in 2003. U.S. intelligence agencies concurred with that assessment in a 2007 report.

Israel contends Iran is still intent on developing a nuclear weapon. It argues Iran’s ballistic missile program and other research could help build a bomb if it pursued one — especially as provisions of the 2015 nuclear deal expire. Iran long has maintained its nuclear program is peaceful and that it has no plans to build an atomic bomb.

Amos Yadlin, a one-time head of Israeli military intelligence who now serves as the director of Tel Aviv University’s Institute for National Security Studies, alleged Fakhrizadeh ran “all covert activities with weaponization of the program.”

The damage of his death “cannot be measured since nobody knows exactly the scope and the depth what the Iranians are doing covertly,” Yadlin said. “But no doubt that he was the core source of authority, knowledge and organization of this program.”

Fakhrizadeh’s killing likely complicates the plans of President-elect Joe Biden, who has said his administration will consider reentering Tehran’s nuclear deal with world powers. It also raises the risk of an open conflict in President Donald Trump’s final weeks in office, as any retaliation could provoke an American military response, Yadlin said.

“I highly recommend to the officials to keep their mouths closed and not leak anything. They’ve already spoke too much,” he said, referring to cryptic remarks by Israel’s Prime Minister Benjamin Netanyahu to his supporters that he could not discuss everything he did last week.

“Any more evidence that will help the Iranians to decide on retaliation against Israel is a mistake,” Yadlin said.

Also read: Iran’s supreme leader vows revenge over slain scientist

Iran’s supreme leader on Saturday demanded the “definitive punishment” of those behind the killing of a scientist who led Tehran’s disbanded military nuclear program, as the Islamic Republic blamed Israel for a slaying that has raised fears of reignited tensions across the Middle East.

After years of being in the shadows, the image of Mohsen Fakhrizadeh suddenly was to be seen everywhere in Iranian media, as his widow spoke on state television and officials publicly demanded revenge on Israel for the scientist’s slaying.

Israel, long suspected of killing Iranian scientists a decade ago amid earlier tensions over Tehran’s nuclear program, has yet to comment on Fakhrizadeh’s killing Friday. However, the attack bore the hallmarks of a carefully planned, military-style ambush, the likes of which Israel has been accused of conducting before.

The attack has renewed fears of Iran striking back against the U.S., Israel’s closest ally in the region, as it did earlier this year when a U.S. drone strike killed a top Iranian general. The U.S. military acknowledged moving an aircraft carrier back into the region, while an Iranian lawmaker suggested throwing out U.N. nuclear inspectors in response to the killing.

Iran’s Supreme Leader Ayatollah Ali Khamenei called Fakhrizadeh “the country’s prominent and distinguished nuclear and defensive scientist.” Khamenei, who has the final say on all matters of state, said Iran’s first priority after the killing was the “definitive punishment of the perpetrators and those who ordered it.” He did not elaborate.

Speaking earlier Saturday, President Hassan Rouhani blamed Israel for the killing.

“We will respond to the assassination of Martyr Fakhrizadeh in a proper time,” Rouhani said. “The Iranian nation is smarter than falling into the trap of the Zionists. They are thinking to create chaos.”

The United Nations called for restraint.

“Of course we condemn any assassination or extra-judicial killing,” said Stephane Dujarric, spokesperson for Secretary-General Antonio Guterres. “We urge restraint and the need to avoid any actions that could lead to an escalation of tensions in the region.”

Both Rouhani and Khamenei said Fakhrizadeh’s death would not stop the nuclear program. Iran’s civilian atomic program has continued its experiments and now enriches a growing uranium stockpile up to 4.5% purity in response to the collapse of Iran’s nuclear deal after the U.S.′ 2018 withdrawal from the accord.

That’s still far below weapons-grade levels of 90%, though experts warn Iran now has enough low-enriched uranium for at least two atomic bombs if it chose to pursue them.

Analysts have compared Fakhrizadeh to being on par with Robert Oppenheimer, the scientist who led America’s Manhattan Project in World War II that created the atom bomb.

Fakhrizadeh headed Iran’s so-called AMAD program that Israel and the West have alleged was a military operation looking at the feasibility of building a nuclear weapon. The International Atomic Energy Agency says that “structured program” ended in 2003. Iran long has maintained its nuclear program is peaceful.

Fakhrizadeh’s widow appeared unnamed on state television in a black chador, saying his death would spark a thousand others to take up his work.

“He wanted to get martyred and his wish came true,” she said.

Hard-line Iranian media has begun circulating memorial images showing Fakhrizadeh standing alongside a machine-gun-cradling likeness of Revolutionary Guard Gen. Qassem Soleimani, whom the U.S. killed in the January drone strike.

Soleimani’s death led to Iran retaliating with a ballistic missile barrage that injured dozens of American troops in Iraq. Tehran also has forces at its disposal all around Israel, including troops and proxies in neighboring Syria, Hezbollah in Lebanon and Islamic Jihad — and to a lesser extent Hamas — in the Gaza Strip. The Iranian Guard’s naval forces routinely shadow and have tense encounters with U.S. Navy forces in the Persian Gulf as well.

Hours after the attack, the Pentagon announced it had brought the USS Nimitz aircraft carrier back into the Middle East, an unusual move as the carrier already spent months in the region. It cited the drawdown of U.S. forces in Afghanistan and Iraq as the reason for the decision, saying “it was prudent to have additional defensive capabilities in the region to meet any contingency.”

Iran has conducted attacks targeting Israeli interests abroad over the killing of its scientists, like in the case of the three Iranians recently freed in Thailand in exchange for a detained British-Australian academic.

Iran also could throw out inspectors from the International Atomic Energy Agency, who have provided an unprecedented, real-time look at Iran’s nuclear program since the deal. Nasrollah Pezhmanfar, a hard-line lawmaker, said a statement calling to expel the “IAEA’s spy inspections” could be read Sunday, the parliament’s official website quoted him as saying.

Friday’s attack happened in Absard, a village just east of the capital that is a retreat for the country’s elite. Iranian state television said an old truck with explosives hidden under a load of wood blew up near a sedan carrying Fakhrizadeh.

As Fakhrizadeh’s sedan stopped, at least five gunmen emerged and raked the car with rapid fire, the semiofficial Tasnim news agency said. The precision of the attack led to the suspicion of Israel’s Mossad intelligence service being involved. The CIA separately declined to comment on the attack Saturday.

State media has only said the attack killed Fakhrizadeh, though a statement Saturday from the European Union described the incident as killing “an Iranian government official and several civilians.” EU officials did not respond to requests for comment.

In Tehran, a small group of hardline protesters burned images of Trump and President-elect Joe Biden, who has said his administration will consider reentering Tehran’s nuclear deal with world powers. While burning an American and Israeli flag, the hard-liners criticized Iran’s foreign minister who helped negotiate the nuclear deal, showing the challenge ahead of Tehran if officials chose to come back the accord.

On Saturday night, the family of Fakhrizadeh gathered at a mosque in central Tehran for his funeral service, a website associated with Iranian state TV reported. The scientist’s body lay in a flag-draped, open coffin, his eyes closed.

Iran’s president vowed Saturday to exact revenge over the killing of a scientist linked to Tehran’s disbanded military nuclear program as he joined other officials in blaming Israel for the slaying.

Israel, long suspected of killing scientists a decade ago amid tensions over Tehran’s nuclear program, has yet to comment on the killing Friday of Mohsen Fakhrizadeh. However, the attack bore the hallmarks of a carefully planned, military-style ambush.

The slaying threatens to renew tensions between the U.S. and Iran in the waning days of President Donald Trump’s term, just as President-elect Joe Biden has suggested his administration could return to Tehran’s nuclear deal with world powers from which Trump earlier withdrew. The Pentagon announced early Saturday that it sent the USS Nimitz aircraft carrier back into the Mideast.

But analysts have compared Fakhrizadeh to being on a par with Robert Oppenheimer, the scientist who led the U.S.′ Manhattan Project in World War II that created the atom bomb.

“We will respond to the assassination of Martyr Fakhrizadeh in a proper time,” Rouhani said.

He added: “The Iranian nation is smarter than falling into the trap of the Zionists. They are thinking to create chaos.”

Friday’s attack happened in Absard, a village just east of the capital that is a retreat for the Iranian elite. Iranian state television said an old truck with explosives hidden under a load of wood blew up near a sedan carrying Fakhrizadeh.

As Fakhrizadeh’s sedan stopped, at least five gunmen emerged and raked the car with rapid fire, the semiofficial Tasnim news agency said.

Fakhrizadeh died at a hospital after doctors and paramedics couldn’t revive him. Others wounded included Fakhrizadeh’s bodyguards. Photos and video shared online showed a Nissan sedan with bullet holes in the windshield and blood pooled on the road.

Hours after the attack, the Pentagon announced it had brought the USS Nimitz aircraft carrier back into the Middle East, an unusual move as the carrier already spent months in the region. It cited the drawdown of U.S. forces in Afghanistan and Iraq as the reason for the decision, saying “it was prudent to have additional defensive capabilities in the region to meet any contingency.”

The attack comes just days before the 10-year anniversary of the killing of Iranian nuclear scientist Majid Shahriari that Tehran also blamed on Israel. That and other targeted killings happened at the time that the so-called Stuxnet virus, believed to be an Israeli and American creation, destroyed Iranian centrifuges.

Those assaults occurred at the height of Western fears over Iran’s nuclear program. Tehran long has insisted its program is peaceful. However, Fakhrizadeh led Iran’s so-called AMAD program that Israel and the West have alleged was a military operation looking at the feasibility of building a nuclear weapon. The International Atomic Energy Agency says that “structured program” ended in 2003.

IAEA inspectors monitor Iranian nuclear sites as part of the now-unraveling nuclear deal with world powers, which saw Tehran limit its enrichment of uranium in exchange for the lifting of economic sanctions.

After Trump’s 2018 withdrawal from the deal, Iran has abandoned all those limits. Experts now believe Iran has enough low-enriched uranium to make at least two nuclear weapons if it chose to pursue the bomb. Meanwhile, an advanced centrifuge assembly plant at Iran’s Natanz nuclear facility exploded in July in what Tehran now calls a sabotage attack.

Fakhrizadeh, born in 1958, had been sanctioned by the U.N. Security Council and the U.S. for his work on AMAD. Iran always described him as a university physics professor. A member of the Revolutionary Guard, Fakhrizadeh had been seen in pictures in meetings attended by Iran’s Supreme Leader Ayatollah Ali Khamenei, a sign of his importance in Iran’s theocracy.

In recent years, U.S. sanctions lists name him as heading Iran’s Organization for Defensive Innovation and Research. The State Department described that organization last year as working on “dual-use research and development activities, of which aspects are potentially useful for nuclear weapons and nuclear weapons delivery systems.”

Iran’s mission to the U.N., meanwhile, described Fakhrizadeh’s recent work as “development of the first indigenous COVID-19 test kit” and overseeing Tehran’s efforts at making a possible coronavirus vaccine.

Also read: Iran scientist linked to military nuclear program killed

Yemen’s Houthi rebels said they struck a Saudi oil facility in the port city of Jiddah early Monday with a new cruise missile, just hours after the kingdom finished hosting its virtual Group of 20 leaders summit.

The kingdom acknowledged the attack hours later. Videos of a small explosion at a Saudi Arabian Oil Co. facility in Jiddah had circulated on social media all day and a satellite photo confirmed damage at the site.

A projectile struck a fuel tank at the Jiddah distribution station and ignited a fire around 3:50 a.m., an unnamed Energy Ministry official said in a statement carried by the state-run Saudi Press Agency.

Col. Turki al-Maliki, a spokesman for the Saudi-led coalition fighting the Iran-backed Houthis in Yemen, blamed the rebels for what he called “a cowardly attack which not only targets the kingdom, but also targets the nerve center of the world’s energy supply and the security of the global economy.”

Brig. Gen. Yehia Sarie, a Houthi military spokesman, tweeted early Monday that the rebels fired a new Quds-2 cruise missile at the facility. He posted a satellite image online that matched Aramco’s North Jiddah Bulk Plant, where oil products are stored in tanks.

That facility is just southeast of Jiddah’s King Abdulaziz International Airport, a major airfield that handles incoming Muslim pilgrims en route to nearby Mecca.

Online videos appeared to show a tank farm similar to the bulk plant on fire, with wailing sirens heard and police cars alongside a highway by the facility. Details of the videos posted predawn Monday matched the general layout of the bulk plant.

A satellite photo from Planet Labs Inc. later published by TankerTrackers.com appeared to show damage to one of the tanks at the bulk plant and what appeared to be fire-suppression foam on the ground near it.

Earlier, the U.S. Consulate in Jiddah said it wasn’t aware of any casualties from the attack. It urged Americans to “review immediate precautions to take in the event of an attack and stay alert in case of additional future attacks.”

Saudi Aramco, the kingdom’s oil giant that now has a sliver of its worth traded publicly on the stock market, did not respond to a request for comment. Its stock traded slightly up Monday on Riyadh’s Tadawul stock exchange as crude oil prices remained steady above $40 a barrel.

The claimed attack comes just after a visit by outgoing U.S. Secretary of State Mike Pompeo to the kingdom to see Crown Prince Mohammed bin Salman, a meeting that reportedly included Israeli Prime Minister Benjamin Netanyahu. The kingdom also just hosted the annual G-20 summit, which concluded Sunday.

A Saudi-led coalition has been battling the Houthis since March 2015, months after the rebels seized Yemen’s capital, Sanaa. The war has ground into a stalemate since, with Saudi Arabia facing international criticism for its airstrikes killing civilians.

The Houthis have used Quds, or “Jerusalem,” cruise missiles to target Saudi Arabia in the past. The Quds-1 has a copy of a small, Czech-made TJ-100 jet engine, with a range of 700 kilometers (435 miles). United Nations experts have said they don’t believe the missiles are built in Yemen and instead have been sold or traded to them in violation of an arms embargo.

Iran uses a copy of TJ-100 engines in its drone program. U.N. experts, Arab countries and the West say Iran supplies arms to the rebels, allegations denied by Tehran.

The Quds-1 was used in a missile-and-drone strike on the heart of the kingdom’s oil industry in 2019 that shook global energy markets. The U.S. believes Iran carried out that attack amid a series of escalating incidents last year between Tehran and Washington, something the Islamic Republic denies.