Australia's prime minister said on Tuesday 11 Australians remained unaccounted for and 13 had been hospitalized after a volcano eruption in New Zealand.

Three Australians were suspected to be among the initial five confirmed dead, Prime Minister Scott Morrison told reporters in Sydney.

"I fear there is worse news to come over the course of perhaps today or over the next few days," Morrison said.

"This is a terrible tragedy, a time of great innocence and joy interrupted by the horror of that eruption," he added.

Australians were the largest group of nationalities that were exploring White Island when it erupted on Monday.

The 24 injured and unaccounted, whose ages range from 17 to 72, had been part of a tour group from the Royal Caribbean cruise ship Ovation of the Seas, which had left Sydney last week for a New Zealand voyage.

Morrison, a former director of the New Zealand Office of Tourism and Sport who has visited White Island in the past, said Australian police who specialize in identifying disaster victims was flying to New Zealand on Tuesday.

Several Australians were in critical condition at burn units in New Zealand hospitals, he said.

Frantic father Brian Dallow, of Adelaide, South Australia, said his lawyer son Gavin Dallow, 53, his partner Lisa Hosking, 48, and her daughter Zoe Hosking, 15, were among those whose fates were uncertain.

"They were in the island, that's now been confirmed, but whether they got off or what happened we don't know," Dallow told Australian Broadcasting Corp.

"This is the worst. If we knew that something happened to them, it would better than this waiting, I can tell you at the moment. Because we just have to hold our horses and hope for the best," he added.

Sydney's Marist College North Shore confirmed a Sydney family of four was missing.

Former student Jesse Langford, his 17-year-old sister Winona Langford and their parents Anthony and Kristine Langford were among those visiting the island from the cruise ship.

"Please have the Langford family in your prayers," principal Duncan Troy wrote in a statement.

A desperate Australian family is also seeking details about Julie Richards, 47, and her 20-year-old daughter Jessica Richards who were booked for a White Island excursion on Monday.

The mother's sister, Barbara Whitehead told the ABC that relatives were "overwhelmed" by a lack of information from authorities.

Ovation of the Seas passenger Donna Field, said at more than $300 per person, the 7-hour White Island tour was among the most expensive day-trip options. Field, an Australian journalist based in Brisbane, Queensland state, said there had been no warning of heightened seismic activity. Field said she had opted for a mountain climb.

Field said the captain has told passengers that they would not continue the cruise until late Tuesday at the earliest and that "they were trying to make the families of those affected — people on board the ship who had not gone on the tour, but their family members had — they are trying to make them as comfortable as possible in this terrible time."

"The best way to describe it is surreal because life on the cruise ship is one big holiday and that continued for a large part — you know, you had the wave pool going and the kids on the climbing wall, people sipping their cocktails, but then lots of people on their phones trying to understand what was going on and people watching the televisions, talking to their loved ones who were checking on them because obviously with 5,000 people on board, there are a lot of uncertain people all around the world trying to find out what happened to their friends and family, and check on them," Field said.

"I think today though, it's all really sad. Everyone's in a bit of shock today, trying to understand how someone's magical holiday can come to such a tragic end," she added.

For years Romi Jan's mornings would begin with the plaintive call to prayer that rang out from the central mosque in disputed Kashmir's largest city. The voice soothed her soul and made her feel closer to God.

Not anymore. For nearly four months now, the voice that would call out five times a day from the minarets of the Jamia Masjid and echo across Srinagar has been silent, a result of India's ongoing security operations in this Muslim-majority region.

"The mosque closure is a relentless agony for me and my family," Jan said. "I can't tolerate it, but I am helpless."

Already one of the most militarized places in the world, last summer India began pouring more troops into its side of Kashmir, which is divided between India and Pakistan and claimed by both in its entirety. It implemented a security lockdown in which it pressed harsh curbs on civil rights, arrested thousands of people, blocked internet and phone service, and shuttered important mosques.

All of this was laying the groundwork for the Hindu nationalist-led government's Aug. 5 decision to strip Kashmir of its semiautonomous status and remove its statehood, moves it knew would be met with fury by Kashmiri Muslims, most of whom want independence or unification with Pakistan. The government said the restrictions were needed to head off anti-India protests and violence.

While some of the conditions have since been eased, some mosques and Muslim shrines in the region either remain shuttered or have had their access limited. Muslims say this is undermining their constitutional right to religious freedom and only deepening anti-India sentiment.

The centuries-old Jamia Masjid, made of brick and wood, is one of the oldest in this city of 1.2 million, where 96% of people are Muslim. When it's open, thousands of people congregate there for prayers.

Romi would take her two children there every day and sit inside the compound while they would play.

"I would forget all my miseries there," she said.

Now, when her kids ask why they can't go to the mosque, she draws a blank face.

"I open my window of the house which faces the mosque and show my kids the soldiers that are stationed outside it," Romi said.

That it's a target for authorities is neither surprising nor new. Friday sermons at the mosque mainly revolve around the Kashmir conflict, and its surrounding neighborhoods are often where stone-throwing protesters clash with government forces as part of an ongoing anti-India rebellion.

Authorities have banned prayers at the mosque for extended periods during unrest in 2008, 2010 and 2016. Official data show the mosque was closed at least 250 days in those three years combined.

Mohammed Yasin Bangi, the 70-year-old whose voice has called out the prayers at the mosque for the last 55 years, said the current restrictions are the worst he has seen.

"During earlier restrictions, we would be sometimes allowed to offer evening prayers. But not even once during this time around," he said. "The closure of the mosque has robbed me of my peace. I've been subjected to spiritual torture."

A top police officer in the city, speaking on condition of anonymity in keeping with department policy, said authorities decided the mosque could reopen last month for Friday prayers but mosque officials refused.

A mosque official speaking on condition of anonymity because he feared reprisals said they refused because authorities sought assurances that there would be no protests or speeches against Indian rule.

Rohit Kansal, Kashmir's chief government spokesman, declined to comment. Officials from the Home Ministry in New Delhi, which oversees internal security in the country, did not respond to requests for comment.

Freedom of religion is enshrined in India's constitution, allowing citizens to follow and freely practice religion. The constitution also says the state will not "discriminate, patronize or meddle in the profession of any religion."

But even before the current security operation in Kashmir, experts say conditions for India's Muslims have been growing worse under Prime Minister Narendra Modi's Bharatiya Janata Party, which came to power in 2014 and won a landslide re-election in May.

In June, the U.S. State Department said in a report that religious freedom in India continued a downward trend in the year 2018. India's foreign ministry rejected the report.

In August, the Organization of Islamic Cooperation raised concerns about India's lockdown in Kashmir and called for authorities to ensure that Kashmiri Muslims could exercise their religious rights.

The ongoing restrictions in Kashmir have also included gatherings at Muslim shrines and religious festivals.

In August, worshipers were told to host the prayers for the festival of Eid-al-Adha inside small neighborhood mosques rather than in the large outdoor gatherings that are normal. In September, authorities banned the annual Muharram processions that mark the martyrdom of the Prophet Muhammad's grandson.

Last month, during the yearly celebration of the birth anniversary of the Prophet Muhammad, authorities blocked all roads leading to Dargah Hazratbal, the region's most revered Muslim shrine. Only a few hundred devotees were allowed to pray there — far fewer than the tens of thousands the event has been known to draw.

Such restrictions are particularly galling to Kashmiri Muslims because they have long complained that the government curbs their religious freedom on the pretext of law and order while promoting and patronizing an annual Hindu pilgrimage to the Amarnath Shrine in Kashmir that draws hundreds of thousands of visitors.

Sheikh Showkat, a professor of international law and human rights at the Central University of Kashmir, warned that such a duality in policy sent a clear message that the government no longer remains impartial toward different religions and further alienates the people of Kashmir.

"It no way augers well for any peace," he said. "Whether it triggers further radicalization or not, it definitely infuriates people about the safety and security of their faith. It can also snowball into a mass mobilization against the state."

Syed Mohammed Tayib Kamili has been leading annual prayers at Kashmir's Khanqah Naqashband shrine since 1976. Indian authorities stopped last month's gathering from taking place.

The decision, which was met with anti-India protests, was the first time the prayers had not been held in the shrine's 399-year history, Kamili said.

"They have not only violated constitution," he said, "but also invited wrath of the divine power."

The UN General Assembly on Monday adopted a resolution calling for the implementation of Olympic Truce for the Tokyo 2020 Olympic Games.

The resolution, entitled "Building a peaceful and better world through sport and the Olympic ideal," urged UN member states to observe the Olympic Truce "individually and collectively," throughout the period from the seventh day before the start of the Olympic Games until the seventh day following the end of the Paralympic Games.

In particular, it called for ensuring the safe passage, access and participation of athletes, officials and all other accredited persons taking part in the games, and contributing to the safe organization of the Games.

Further, the resolution decided that the 76th session of the General Assembly, set to start in September 2021, should discuss similar matters for the Olympic Winter Games and the Paralympic Winter Games to be held in Beijing in 2022.

Three Australians are believed to be among those killed in New Zealand's volcanic explosion, Prime Minister Scott Morrison said in a press conference on Tuesday morning.

Morrison said 24 Australians aged between 17 and 72 were on a tour of White Island on Monday when the volcano erupted, and 13 of them are hospitalised across multiple hospitals in New Zealand, with 11 Australians still "unaccounted for."

"But with 11 Australians unaccounted for, three of those are feared to be amongst the five that have already been identified as deceased."

The first victim has been identified by the local media as Hayden Marshall-Inman, a local tour guide.

"This is a very, very hard day for a lot of Australian families whose loved ones have been caught up in this terrible, terrible tragedy," Morrison said.

"A time of great innocence and joy interrupted by the horror of that eruption," he said, expressing gratitude to the New Zealand government and the country's Prime Minister Jacinda Ardern.

"I want to thank all of those who risked their lives yesterday, put themselves in harm's way to protect others," he said.

"These horrible incidents are always accompanied by incredibly selfless acts. And equally I want to thank all of those in the medical teams who are there caring for Australians right now in New Zealand hospitals."

Researchers from Australia's University of New South Wales (UNSW) found that using a drone to monitor hippos was significantly more cost effective and more accurate than previous ground surveys.

With hunting and habitat loss driving wild hippo populations further into decline, keeping track of the semi-aquatic African mammals' numbers is now a critical focus for conservation efforts.

Observing the species from land can prove difficult and extremely dangerous. As well as being hard to spot in the water, Hippopotamus amphibious are very territorial and often do not take kindly to unwanted visitors.

That's why researchers from UNSW decided to take a different approach when it comes to tracking Africa's most deadly mammal.

They measured hippo populations in Botswana's Okavango Delta region for seven days with drone surveillance technology in a collaboration with Elephants Without Borders.

"Even though hippos are a charismatic megafauna, they are surprisingly understudied, because of how difficult it is to work with nocturnal, amphibious and aggressive animals," Victoria Inman, lead author and PhD candidate at the UNSW, said on Tuesday.

"(But) our study shows that small, commercially available drones are a simple, affordable and effective method for wildlife conservation organizations to monitor threatened species."

"Long-term statistics on animal populations are critical for understanding the nature and extent of species' declines."

"Drone data could be routinely collected in different river systems, providing a guide to the numbers in hippo pods, seasonal changes and the ability to track the long-term status of hippo populations."

Seeing the use of drones as an increasingly valuable tool for observing wildlife populations, co-author of the study and Director of the Centre for Ecosystem Science at UNSW Professor Richard Kingsford said the bird's eye view also allowed the team to determine the age of individual hippos based on their body lengths.

"This method will be important for monitoring the age structure of hippo populations in different parts of Africa and to track breeding," he said.

"Importantly, our surveys also effectively tracked changes in the hippo pod over time, as adults emigrated from the lagoon as it dried - a typical response of hippos to changing water availability."

"Drones also provide a viable alternative to land-based counts and have low impact on hippos, offering further opportunities to survey inaccessible areas and, just as critically, collect this information safely," he said.