The United Nations Interim Force in Lebanon said Thursday that a peacekeeper was killed and two others wounded when shelling hit their base in the country's south the previous night.
"A UNIFIL peacekeeper died early this morning from critical injuries sustained when mortar shells struck his position," a statement from the force said, adding that an investigation had been launched.
Meanwhile, Israel struck south Lebanon on Thursday and threatened new attacks on Beirut despite an announcement hours earlier that Israel and Lebanon had agreed to implement a conditional ceasefire.
Israeli and Lebanese envoys held a fourth round of talks in Washington on Wednesday, agreeing to implement a ceasefire hinged on Iran-backed militant group Hezbollah halting its attacks.
But Hezbollah, which rejects the direct Israel-Lebanon talks, has not commented on the announcement, while Israel's Defence Minister, Israel Katz, said military operations would continue in south Lebanon .
The army will "at this stage, continue its fire and ground operations, remain in the security zone in Lebanon up to the Yellow Line—including in the Beaufort area—and without the return of the population, while continuing to dismantle terrorist infrastructure on the ground," he said.
A 17 April truce was meant to halt the fighting and was extended several times, but has never been observed, notably by Israel.
Lebanon's state-run National News Agency ( NNA) reported strikes along roads at several southern locations on Thursday, with a couple and their daughter wounded in an attack on their car.
Israel's military renewed a warning to Lebanese not to go south of the Zahrani River, around 45 kilometres, after it declared all areas south of the river "combat zones" last week.
Earlier Thursday, the Israeli military said air raid sirens were sounded in northern Israel, with one incident involving a "suspicious aerial target" resolved, while another incident was found to be a false alarm.
Before the announcement, Hezbollah said it had launched rockets and drones early Thursday at Israeli troops who had invaded southern Lebanon.
Israel's far-right National Security Minister Itamar Ben Gvir criticised the deal, calling it a "serious mistake".
According to a statement issued after the meeting, the two sides, which do not have formal diplomatic relations, also agreed to create "pilot zones" in which the Lebanese armed forces "will take exclusive control of the territory to the exclusion of all non-state actors".
More Lebanon-Israel talks are scheduled for later this month.
Senior Hezbollah official Mahmud Qomati had told AFP this week that the group would "not accept a partial ceasefire".
On Wednesday, US President Donald Trump said he wanted to separate talks on the conflict in Lebanon from those on the war with Iran.
Tehran, however, insists the conflicts are linked, and its Foreign Minister Abbas Araghchi warned that any attack on Beirut would trigger a "full-scale resumption" of war.
Israeli attacks have killed more than 3,500 people in Lebanon since 2 March alone.