Israeli Prime Minister Benjamin Netanyahu on Monday vowed to hit Hezbollah without mercy, a day after the Iran-backed Lebanese group's deadliest strike on Israel since the start of the war in late September. 

Hezbollah's drone attack on an Israeli base killed four soldiers on Sunday, while volunteer rescuers said another 60 people were injured.

"We will continue to mercilessly strike Hezbollah in all parts of Lebanon –- including Beirut," Netanyahu said on a visit to the base near Binyamina, south of Haifa.

Hezbollah said it launched the "squadron of attack drones" in response to Israeli attacks, including one last week that Lebanon's health ministry said killed at least 22 people in central Beirut.

Since Israel last month escalated its bombing in Lebanon before sending ground troops across the frontier, the war has killed at least 1,315 people, according to an AFP tally of Lebanese health ministry figures, though the real toll is likely higher.

Prior to Netanyahu's comments, new air strikes had already occurred against targets around Lebanon, including one in a northern Christian-majority village which killed at least 21 people on Monday, according to the health ministry.

Hezbollah said on Monday around midday that it had launched rockets at a naval base near Haifa before a further "big rocket salvo" in the early evening at the northern Israeli town of Safed.

Its fighters were also "engaged in violent clashes" in the Lebanese frontier village of Aita al-Shaab, and were fighting elsewhere as well, it said.

Air raid sirens sounded across central Israel in the early evening, including in the commercial hub of Tel Aviv, the military said, after it earlier reported the interception of two drones approaching from Syria.

'Deeply worrying'

Israel wants to push back Hezbollah in order to secure its northern boundary and allow tens of thousands of people displaced by rocket fire since last year to return home safely. 

Hezbollah says its strikes are in support of Palestinian militants Hamas who attacked Israel on October 7 last year, triggering the ongoing war with Israel in the Gaza Strip.

The International Organization for Migration said last week it had verified 690,000 people displaced by the war in Lebanon.

The International Committee of the Red Cross's regional director, Nicolas Von Arx, appealed for the protection of ambulances and other health facilities and personnel, calling attacks on them "deeply worrying."

Israel faced new criticism over injuries and damage sustained by the UN peacekeeping force which has been deployed in Lebanon since 1978, after a previous Israeli invasion. 

The UN Security Council for the first time on Monday expressed "strong concerns" over peacekeepers being wounded.

The council unanimously "urged all parties to respect the safety and security of UNIFIL personnel and premises."

Netanyahu earlier said Israel's military "is doing its utmost to prevent such incidents" and repeated his request that the peacekeepers "get out of harm's way."

UNIFIL has refused.

"The decision was made that UNIFIL would currently stay in all its positions in spite of the calls that were made by the Israel Defense Forces to vacate the positions that are in the vicinity of the Blue Line," UN peacekeeping chief Jean-Pierre Lacroix said. 

"I want to emphasize that this decision still remains," he said, adding that the plan was confirmed earlier Monday by Secretary-General Antonio Guterres.

Anti-missile defense

Prime Minister Simon Harris of Ireland, which has troops in the UNIFIL mission, on Monday told Israeli President Isaac Herzog in a phone call that UNIFIL has "a clear mandate from the Security Council, and that it must be allowed to carry out its functions unimpeded," Harris's office said.

The Hamas attack on Israel last year which triggered war in Gaza resulted in the deaths of 1,206 people, mostly civilians, according to an AFP tally of official Israeli figures.

The number includes hostages killed in captivity.

Israel's retaliatory military campaign in Gaza has killed 42,289 people, the majority civilians, according to the health ministry in the Hamas-run territory. The UN has described the figures as reliable.

Since the Gaza war began hundreds of Palestinians have also been killed in the occupied West Bank. On Monday Palestinian officials said Israeli forces killed two more during a raid. Israel said it was "looking into the reports."

In Gaza, despite escalating Israeli military operations in central and northern areas, the second round of a polio vaccination campaign for hundreds of thousands of children began on Monday.

With the war there and in Lebanon, showing no sign of abating, fears of even wider regional conflict have seen Iran, which backs Hezbollah and Hamas, engage in diplomatic efforts with allies and other powers.

Iranian Foreign Minister Abbas Araghchi met a senior official from Yemen's Iran-backed Huthi movement in Oman, his latest stop on a regional diplomatic tour.

Jordan's King Abdullah II warned of "a regional war that will be costly for everyone," during a meeting with Lebanon's Prime Minister Najib Mikati on Monday. 

Israel is still weighing its response to an October 1 missile attack by Iran, the latest of two it has carried out against Israel this year.

by Aya Iskandarani with Jay Deshmukh in Jerusalem