Multiple Israeli air strikes have killed at least 21 people in southern Lebanon, while Beirut's southern suburbs have been hit for the first time in nearly a week.

Mayor Ahmad Kahil of the town of Nabatiyeh was among those killed, the region's governor, Howaida Turk, told The Associated Press.

Mr Turk said there had been 11 strikes on the town and its surroundings, adding the intense raids "formed a kind of belt of fire" in the area.

It was the most significant Israeli hit yet on a Lebanese state building since it expanded its offensive last month and came despite US concerns about rising death tolls and the prospect of all-out war in the oil-producing Middle East.

After Israel first issued an evacuation notice for Nabatieh, a city of tens of thousands of people, on October 3, a Reuters reporter called Mayor Ahmed Kahil to ask if he would leave.

He said he would not.

Lebanon's caretaker prime minister, Najib Mikati, accused Israel of "intentionally targeting" a meeting of the municipal council convened to discuss relief efforts.

He accused the international community of being "deliberately silent" about Israeli strikes that have killed civilians and attacks on UN peacekeepers.

"What solution can be hoped for in light of this reality?" he said in a statement.

Earlier this week, Israeli air strikes destroyed Nabatiyeh's century-old market area.

Further south, at least 15 people were reported dead in the town of Qana, which has long been associated with civilian deaths after Israeli strikes during previous conflicts with Hezbollah.

There was no immediate comment from the Israeli military on the strikes in Qana late on Tuesday local time.

Lebanon's Civil Defense said 15 bodies had been recovered from the rubble of a building and that rescue efforts were still underway.

In 1996, Israeli artillery shelling on a United Nations compound housing hundreds of displaced people in Qana killed at least 100 civilians and wounded scores more, including four UN peacekeepers.

During the 2006 war, an Israeli strike on a residential building killed nearly three dozen people, a third of them children. Israel said at the time that it struck a Hezbollah rocket launcher behind the building.

In Beirut, the neighbourhood of Haret Hreik was struck after Israel Defense Forces (IDF) spokesperson Avichay Adraee warned people to leave the area.

"You are located near facilities and interests affiliated with Hezbollah, which the IDF will work against in the near future," Mr Adraee wrote in Arabic on X before the strikes, addressing the Haret Hreik residents.

The strikes on southern Beirut were the first in six days, and came after Mr Mikati said the United States had given him assurances that Israel would curb its strikes on the capital. There was no immediate word on casualties.

Hezbollah has a strong presence in southern Beirut, known as the Dahiyeh, which is also a residential and commercial area home to large numbers of civilians and people unaffiliated with the militant group.

At least 1,356 people have been killed in Lebanon since Israel escalated its bombing last month, according to an AFP tally of Lebanese health ministry figures, however, the real toll is likely to be higher.

The 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.

Netanyahu rejects calls for ceasefire

Israeli Prime Minister Benjamin Netanyahu dismissed calls for a ceasefire in Lebanon, saying it would leave Hezbollah forces near his country's border.

The vow to keep fighting Hezbollah came as the United States ramped up pressure on Israel over its military's conduct in Lebanon and Gaza, criticising the recent bombing of Beirut and demanding more aid reach the Palestinian territory.

In a call with French President Emmanuel Macron, Mr Netanyahu said he was "opposed to a unilateral ceasefire which does not change the security situation in Lebanon and which will only return it to the way it was", according to a statement from his office.

Mr Netanyahu and the Israeli military have insisted there must be a buffer zone free of Hezbollah fighters along Israel's border with Lebanon.

Hezbollah began firing rockets into Israel on October 8 in solidarity with the Palestinian militant group Hamas.

A year of low-level fighting along the Israel-Lebanon border escalated into all-out war last month and has displaced some 1.2 million people in Lebanon.

Hezbollah's rocket attacks, which have extended their range and grown more intense over the past month, have driven around 60,000 Israelis from their homes in the north.

In a defiant televised speech, Hezbollah's deputy leader Naim Qassem called for a ceasefire but also threatened to expand the scope of the group's missile strikes across Israel.

"Since the Israeli enemy targeted all of Lebanon, we have the right from a defensive position to target any place in Israel," he said.

Lebanon says children among the dead

Early on Wednesday Israel's military said about 50 projectiles were fired from Lebanon at Israel's north, without any reports of casualties.

Iran-backed Hezbollah said it launched "a large salvo of missiles" at the city of Safed.

Israel's military bombed several areas in southern and eastern Lebanon on Tuesday, including in the Bekaa Valley where a hospital in Baalbek city was put out of service, Lebanon's official National News Agency reported.

It also said it had captured three Hezbollah fighters in south Lebanon.

Lebanon's health ministry said nine people were killed on Tuesday evening in strikes on the country's south, and five others in the east, including three children.

Asked about Israeli air strikes in Lebanon, in which residential buildings in central Beirut were hit on October 10, the US State Department voiced open criticism.

"We have made clear that we are opposed to the campaign the way we've seen it conducted over the past weeks," State Department spokesperson Matthew Miller told reporters.

In a letter sent to the Israeli government on Sunday, US Secretary of State Antony Blinken and Defense Secretary Lloyd Austin also warned that the United States could withhold weapons deliveries unless more humanitarian aid was delivered to Palestinians in Gaza.

'Worst restrictions' since October 7

Despite the need for food, medical supplies and shelter in hunger-ravaged Gaza, a spokesman for UN children's agency UNICEF said aid was facing the tightest restrictions since the start of Israel's offensive in October last year.

"We see now what is probably the worst restrictions we've seen on humanitarian aid, ever," UNICEF spokesman James Elder said in Geneva, adding there were "several days in the last week [where] no commercial trucks whatsoever were allowed to come in".

The head of UNRWA, the UN agency for Palestinian refugees, had an even more dire assessment.

"I will not hide the fact that we might reach a point that we won't be able anymore to operate," Philippe Lazzarini told journalists at a news conference in Berlin.

"We are very near to a possible breaking point. When will it be? I don't know. But we are very near of that," he said.

He said the agency was facing a combination of financial and political threats to its existence, in addition to difficulties in day-to-day operations.

He said there was a real risk, heading into winter, with people's immune systems weakened, that famine or acute malnutrition could become a likelihood.

UNRWA provides education, health and aid to millions of Palestinians in Gaza, the West Bank, Jordan, Lebanon and Syria.

It has long had tense relations with Israel but ties have deteriorated sharply since the start of the war in Gaza.

For more than a week, Israeli forces have engaged in a sweeping air and ground assault targeting northern Gaza and the area around Jabalia amid claims Hamas militants were regrouping there.

"The whole area has been reduced to ashes," said Rana Abdel Majid, 38, from the Al-Faluja area of northern Gaza.

Ms Majid said entire blocks had been levelled by "the indiscriminate, merciless bombing".

At a school-turned-shelter hit by an Israeli strike in the central Nuseirat camp, Fatima al-Azab said there was "no safety anywhere" in Gaza.

Israel launched a military campaign in Gaza after an October 7, 2023, terror attack by Hamas that resulted in the deaths of around 1,200 people, mostly civilians, and another 250 were abducted, according to official Israeli figures.

The Israeli campaign has killed 42,344 people, the majority of them civilians, according to Palestinian health authorities.

Gaza destruction up to $30 billion

The cost of destructive Israeli strikes on Gaza was now probably in the range of $US14 to 20 billion ($21 to 30 billion), and the destruction caused by Israel's bombing of southern Lebanon would add to that regional total, World Bank president Ajay Banga said on Tuesday.

"The economic impact of this war, on the other hand, depends a great deal on how much this spreads."

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