The Israeli military said it struck Hezbollahs headquarters in Beirut on Friday in a series of massive explosions that targeted the leader of the militant group and levelled multiple high-rise apartment buildings.

At least six people were killed and 91 were wounded, Lebanons health ministry said. It was the biggest blast to hit the Lebanese capital in the past year and appeared likely to push the escalating conflict closer to full-fledged war.

Hezbollah leader Hassan Nasrallah was the target of the strikes on the groups headquarters, according to two people familiar with the matter who requested anonymity, including one United States official. The Israeli army declined to comment on who it was targeting. It was not immediately clear if Nasrallah was at the site, and Hezbollah did not comment on the report.

The death toll is likely to rise significantly as teams are still combing through the rubble of six buildings. Israel launched a series of strikes on other areas of the southern suburbs following the initial blast.

After the strikes, Prime Minister Benjamin Netanyahu abruptly cut short a visit to the United States to return home. Hours earlier, he addressed the United Nations, vowing that Israels intensified campaign against Hezbollah over the past two weeks would continue -- further dimming hopes for an internationally backed ceasefire.

News of the blasts came as Netanyahu was briefing reporters after his UN address. A military aide whispered into his ear, and Netanyahu quickly ended the briefing.

Israeli army spokesperson Rear Adm. Daniel Hagari said the strikes targeted the main Hezbollah headquarters, saying it was located underground beneath residential buildings.

The series of blasts at around nightfall reduced six apartment towers to rubble in Haret Hreik, a densely populated, predominantly Shiite district of Beiruts Dahiyeh suburbs, according to Lebanons national news agency. A wall of billowing black and orange smoke rose into the sky as windows were rattled and houses shaken some 30 kilometres (18 miles) north of Beirut.

Footage showed rescue workers clambering over large slabs of concrete, surrounded by high piles of twisted metal and wreckage. Several craters were visible, one with a car toppled into it. A stream of residents carrying their belongings were seen fleeing along a main road out of the district.

Israel provided no immediate comment about the type of bomb or how many it used but the resulting explosion levelled an area greater than a city block. The Israeli army has in its arsenal 2,000 pound American-made Bunker Buster guided bombs designed specifically for hitting subterranean targets.

Richard Weir, crisis and weapons researcher with Human Rights Watch, said the blasts were consistent with that class of bomb.

Israels air forces followed with a new set of strikes early Saturday, also in the southern suburbs, shortly after warning residents of three buildings to evacuate, saying they were being used by Hezbollah to hide weapons, including anti-ship missiles. Israels military announced additional attacks on Beqaa in eastern Lebanon and Tyre in the south.

To a degree unseen in past conflicts, Israel this past week has aimed to eliminate Hezbollahs senior leadership. But an attempt to assassinate Nasrallah -- successful or not -- would be a major escalation. The Pentagon said the U.S. had no advance warning of the strikes.

Nasrallah has been in hiding for years, very rarely appearing in public. He regularly gives speeches, but always by video from unknown locations. The site hit Friday evening had not been publicly known as Hezbollahs main headquarters, though it is located in the groups security quarters, a heavily guarded part of Haret Hreik where it has offices and runs several nearby hospitals.

Four hours after the strike, Hezbollah had still not issued any statement referring to it. Instead, it announced that it had launched a salvo of rockets at the Israeli city of Safed, which it said was in defence of Lebanon and its people, and in response to the barbaric Israeli violation of cities, villages and civilians. The Israeli military said a house and a car in Safed were hit, and officials said a 68-year-old woman suffered mild shrapnel wounds.

Israel dramatically intensified its airstrikes in Lebanon this week, saying it is determined to put an end to more than 11 months of Hezbollah fire into its territory. The escalated campaign has killed more than 720 people in Lebanon, including dozens of women and children, according to Health Ministry statistics. A predawn strike Friday in the mainly Sunni border town of Chebaa killed nine members of the same family, the state news agency said.

The scope of Israels operation remains unclear, but officials have said a ground invasion to push the militant group away from the border is a possibility. Israel has moved thousands of troops toward the border in preparation.

At the UN, Netanyahu vowed to continue degrading Hezbollah until Israel achieves its goals. His comments dampened hopes for a U.S.-backed call for a 21-day truce between Israel and Hezbollah to allow time for a diplomatic solution. Hezbollah has not responded to the proposal.

Iranian-backed Hezbollah, the strongest armed force in Lebanon, began firing rockets into Israel almost immediately after Hamas Oct. 7 attack, saying it was a show of support for the Palestinians. Since then, it and the Israeli military have traded fire almost daily, forcing tens of thousands of people to flee their homes on both sides of the border.

An Israeli security official said he expects the campaign against Hezbollah would not last for as long as the current war in Gaza, because the militarys goals are much narrower.

In Gaza, Israel aims to dismantle Hamas military and political regime, but the goal in Lebanon is to push Hezbollah away from the border -- not a high bar like Gaza in terms of operational objectives, said the official, who spoke on the condition of anonymity due to military briefing guidelines.

The Israeli military said it carried out dozens of strikes around the south Friday, targeting targeting Hezbollah rocket launchers and infrastructure. It said Hezbollah fired a volley of rockets toward the northern Israeli city of Tiberias.

In the southern Lebanese city of Tyre, civil defence workers pulled the bodies of two women -- 35-year-old Hiba Ataya and her mother Sabah Olyan -- from the rubble of a building brought down by a strike.

Thats Sabah, these are her clothes, my love, one man cried out as her body emerged.

Israel says its accelerated strikes this week have already inflicted heavy damage on Hezbollahs weapons capabilities and its fighters. But the group boasted a large arsenal of rockets and missiles and its remaining capacities remain unknown.

Hezbollah officials and their supporters remain defiant. Not long before the explosions Friday evening, thousands massed in another part of Beiruts suburbs for the funeral of three Hezbollah members killed in earlier strikes, including the head of the groups drone unit, Mohammed Surour.

People in the giant crowd waved their fists in the air and chanted, We will never accept humiliation, as they marched marched behind the three coffins, wrapped in the groups yellow flag.

Hussein Fadlallah, Hezbollahs top official in Beirut, said in a speech that no matter how many commanders Israel kills, the group has endless numbers of experienced fighters. He vowed that Hezbollah will keep fighting until Israel stops its offensive in Gaza.

We will not abandon the support of Palestine, Jerusalem and oppressed Gaza, Fadlallah said. There is no place for neutrality in this battle.