Lebanese officials denounced the incident, which also wounded more than 50 people in Nabatieh, a provincial capital, saying it was proof Israel's campaign against the Hezbollah armed group was now shifting to target the Lebanese state.
The Israelis "intentionally targeted a meeting of the municipal council to discuss the city's service and relief situation" to aid people displaced by the Israeli campaign, caretaker Prime Minister Najib Mikati said.
Israel launched its ground and air campaign in Lebanon to dismantle Hezbollah after a year during which the Iran-backed militant group fired across the border in support of Palestinian militants Hamas in Gaza.
Israel first issued an evacuation notice for Nabatieh's tens of thousands of residents on October 3. (AP PHOTO)
Fears of a regional conflict have grown after Israel promised to retaliate for an Iranian missile attack on October 1.
The US said on Wednesday it struck five underground weapons storage locations in Houthi-controlled areas of Yemen, the latest in more than a dozen US attacks on Houthi-linked targets this month.
Iran-aligned Houthi fighters in Yemen who say they are acting in solidarity with Palestinians in Israel's year-long war in Gaza have carried out nearly 100 attacks on ships crossing the Red Sea since November.
Israel also launched strikes at Syria's Mediterranean port city of Latakia early on Thursday, Syrian state news agency SANA reported.
Firefighters are working on extinguishing fires that had broken out, SANA added, while Syrian state TV reported the country's air defences had confronted Israeli targets over Latakia.
Two people were injured and private properties were damaged, state media reported citing a military statement.
Israel first issued an evacuation notice for Nabatieh, a city of tens of thousands of people, on October 3. At the time, the city's Mayor Ahmed Kahil told Reuters he would not leave.
Asked about the Israeli strike on Nabatieh, State Department spokesperson Matthew Miller declined to comment on the circumstances of specific strikes but said the US understands Hezbollah operates from places including civilian homes and supported limited strikes to target the group.
"Obviously, we'd not want to see entire villages destroyed. We don't want to see civilian homes destroyed," Miller said.
Israel said on Wednesday it struck dozens of Hezbollah targets in the Nabatieh area and its navy also hit dozens of targets in southern Lebanon.
It said it had "dismantled" a tunnel network used by Hezbollah's elite Radwan Forces in the heart of a town near the border with Israel, publishing a video showing multiple explosions rocking a cluster of buildings. Lebanese officials said it was the small town of Mhaibib.
Israeli operations killed at least 2350 people over the past year, Lebanon's health ministry says. (AP PHOTO)
Israeli operations in Lebanon have killed at least 2350 people over the last year, according to the health ministry, and more than 1.2 million people have been displaced. The death toll does not distinguish between civilians and combatants but includes hundreds of women and children.
Around 50 Israelis, both soldiers and civilians, have been killed in the same period, according to Israel.
The UN mission in Lebanon (UNIFIL) said its peacekeepers observed an Israeli tank firing at their watchtower near southern Lebanon's Kfar Kela on Wednesday morning. Two cameras were destroyed, and the tower was damaged, UNIFIL said.
There was no immediate comment from the Israeli military on the UNIFIL statement.
Israel has previously called on the United Nations to move members of the UNIFIL peacekeeping force in southern Lebanon out of the combat zone for their safety.
UNIFIL says its troops have come under Israeli attack several times, though Israel has disputed accounts of those incidents.
