At least 18 people were killed in southern Lebanon following a series of Israeli air strikes overnight, Lebanon's health ministry said, while the Israeli military reported that four of its soldiers were killed in attacks by Hezbollah.
The Israel Defense Forces (IDF) said it struck around 80 Hezbollah-linked targets and killed dozens of fighters from the Iran-backed armed group.
The latest violence came just a day after the United States and Iran signed an agreement aimed at ending the conflict across the Middle East, including a permanent ceasefire in Lebanon.
Despite the deal, both Israel and Hezbollah have continued exchanging attacks, raising doubts about the future of the fragile truce. The agreement calls for an end to hostilities on all fronts and respect for Lebanon's territorial integrity and sovereignty.
However, Israel has made clear that it does not plan to withdraw its forces from Lebanon, arguing that its campaign against Hezbollah is separate from the broader conflict involving Iran.
Lebanon's state news agency described Thursday night's bombardment across the Nabatieh district in southern Lebanon as among the heaviest since the war began. It reported at least 18 deaths, 33 injuries and damage to several buildings.
Hezbollah said its fighters ambushed an Israeli military unit in southern Lebanon, destroying three tanks with guided missiles and targeting troops with rocket and artillery fire.
Israeli Prime Minister Benjamin Netanyahu expressed condolences over the deaths of the four soldiers and said he had ordered the military to intensify operations against Hezbollah.
"My directive is clear: Israel will not tolerate attacks on our soldiers or our territory, and it will exact a very heavy price from Hezbollah for these attacks," Netanyahu wrote on X.
Lebanon became involved in the wider conflict shortly after it began when Hezbollah launched rockets into Israel following a strike that killed Iran's supreme leader.
Israel responded with an extensive military campaign across Lebanon and occupied parts of southern Lebanon, saying its goal was to push Hezbollah fighters away from its northern border.
According to Lebanon's health ministry, at least 3,912 people, including women and children, have been killed and another 11,699 wounded since the latest conflict began.
Around one million people remain displaced, while dozens of communities in southern Lebanon have been completely destroyed.
Hezbollah has vowed to continue its attacks as long as Israeli forces remain in Lebanese territory.
Netanyahu is also facing pressure at home to maintain military operations against Hezbollah, a position that could further strain relations with US President Donald Trump, who has publicly criticised Israel's actions in Lebanon.
Israeli National Security Minister Itamar Ben-Gvir reacted to the deaths of the four soldiers by saying that "all of Lebanon must burn."
"With all due respect to the Americans, Israel must make it clear to the entire world that the blood of our sons and the security of our citizens are not up for bargaining," he said.
French Foreign Minister Jean-Noël Barrot urged Israel to respect the agreement and called on the United States to pressure the Israeli government to comply with its commitments.
The US-Iran agreement signed on Thursday includes provisions related to Iran's nuclear programme, sanctions relief and a commitment by both sides to seek a final settlement within 60 days, with the possibility of extending the deadline by mutual consent.
A new round of direct talks scheduled in Switzerland on Friday was postponed after US Vice President JD Vance cancelled his planned visit.
Vance has previously criticised some members of Netanyahu's cabinet for opposing the agreement.
"If I was in the cabinet of the Israeli government, I might not be attacking the only powerful ally that I have anywhere left in the entire world," he told reporters.
In an interview with the New York Times, Vance singled out Ben-Gvir and Finance Minister Bezalel Smotrich as critics of the deal.
"I guess my response to them would be, what is your exact proposal? You're a country of nine million people. You can't just kill your way out of solving every single national security problem that you have," he said.
Netanyahu, meanwhile, stressed the importance of maintaining close ties with Washington, saying the United States had stood "shoulder to shoulder" with Israel during the war with Iran.
Recent reports, however, suggest tensions have emerged between the two allies, with leaks indicating that Trump has expressed frustration with Netanyahu during private phone conversations.
US officials have maintained that while Lebanon is covered by the ceasefire framework, the withdrawal of Israeli troops from Lebanese territory is not a condition of the agreement and that Israel retains the right to self-defence.
#Reports BBC