BEIRUT, Lebanon, Sept 20, 2024 (AFP) - A strike on Hezbollah's stronghold in Lebanon's capital Beirut on Friday killed eight people and wounded dozens of others, with a source close to the movement saying a top military leader was dead.

The Israeli military said it had conducted a "targeted strike", while the Lebanese health ministry said the attack had killed eight people and wounded 59 more.

Requesting anonymity to discuss sensitive matters, the source close to Hezbollah said the strike on the group's stronghold in south Beirut had killed the head of its elite Radwan unit, Ibrahim Aqil.

The air strike is the third to hit the southern suburbs of Beirut since the start of the Israel-Hamas war on October 7, with the focus of the violence shifting dramatically this week from Gaza to Lebanon.

Earlier this year, strikes blamed on Israel killed a top commander of Hezbollah, Fuad Shukr, and a leader of its allied Palestinian group Hamas, Saleh al-Aruri.

"The Israeli air strike killed Radwan Force commander Ibrahim Aqil, its armed force's second-in-command after Fuad Shukr," the source close to Hezbollah said.

Hezbollah has not officially confirmed his death, but it said after the strike that it had hit an Israeli intelligence base it claimed was responsible for unspecified "assassinations".

The United States had offered a $7 million reward for information on Aqil, describing him as a "principal member" of the organisation that claimed the bombing of the US embassy in Beirut in 1983 that killed 63 people.

Footage posted on social media and verified by AFP showed smoke rising over southern Beirut on Friday.

- Communication device explosions -

Israeli troops and Hezbollah fighters have battled each other along the Israel-Lebanon border since Hamas sparked the war in Gaza with its October 7 attack.

The focus of Israel's firepower for nearly a year has been on Gaza, but with Hamas much weakened, the focus of the war has shifted dramatically to Israel's northern border.

Months of near-daily border clashes have killed hundreds in Lebanon, most of them fighters, and dozens in Israel, and forced thousands on both sides to flee their homes.

On Tuesday and Wednesday, Hezbollah was hit by an unprecedented attack that it has blamed on Israel, though Israel has yet to comment.

The attack saw thousands of Hezbollah operatives' communication devices explode across two days, killing 37 people and wounding thousands more.

Hezbollah chief Hassan Nasrallah vowed on Thursday that Israel would face retribution for the blasts.

Earlier Friday, Israel said Hezbollah had fired dozens of rockets from Lebanon following air strikes which destroyed dozens of the group's launchers.

Israel announced this week it was shifting its war objectives to its northern border with Lebanon.

Speaking to troops on Wednesday, Israeli Defence Minister Yoav Gallant said: "Hezbollah will pay an increasing price" as Israel tries to "ensure the safe return" of its citizens to border areas.

"We are at the start of a new phase in the war," he said.

Israeli Prime Minister Benjamin Netanyahu meanwhile delayed his scheduled departure to the United States, where he is due to address the UN General Assembly, by a day, with an official citing the situation on the northern front.

Earlier Friday, Hezbollah said it targeted at least six Israeli military bases with salvos of rockets after overnight bombardment that people in south Lebanon described as among the fiercest so far.

- 'Fear of wider war' -

Residents of Marjayoun, a Lebanese town close to the border, said the overnight bombardment was among the heaviest since the border clashes began last October.

"We were very scared, especially for my grandchildren," said Nuha Abdo, 62. "We were moving them from one room to another."

Clothing store owner Elie Rmeih, 45, counted more than 50 strikes.

"It was a terrifying scene and unlike anything we have experienced since the escalation began.

"We live in fear of a wider war, you don't know where to go."

- Calls for restraint -

International mediators have been scrambling to stop the Gaza war from turning into an all-out regional conflict.

US Secretary of State Antony Blinken, who has been scrambling to salvage efforts for a Gaza ceasefire and hostage release deal, called for restraint on all sides.

"We don't want to see any escalatory actions by any party" that would endanger the goal of a Gaza ceasefire, he said.

Hamas's October 7 attacks that sparked the Gaza war resulted in the deaths of 1,205 people, mostly civilians, on the Israeli side, according to an AFP tally based on Israeli official figures that include hostages killed in captivity.

Out of 251 hostages seized by Hamas, 97 are still held in Gaza, including 33 the Israeli military says are dead.

Israel's retaliatory military offensive has killed at least 41,272 people in Gaza, most of them civilians, according to figures provided by the Hamas-run territory's health ministry. The United Nations has acknowledged the figures as reliable.