Hezbollah has confirmed its leader for the past three decades, Hassan Nasrallah, was killed in an Israeli airstrike in Lebanon on Friday and vowed to continue the battle against Israel.

The Israeli military said Nasrallah was killed in a "targeted strike" on what it identified as the group's underground headquarters beneath a residential building in Dahiyeh — a Hezbollah-controlled southern suburb of Beirut.

It said he was killed along with another top leader, Ali Karaki, and other commanders with Hezbollah, a Lebanon-based Shia militant group formed in 1982 primarily to combat Israeli forces in southern Lebanon.

A statement from Hezbollah issued Saturday said Nasrallah "has joined his fellow martyrs" and it vowed to "continue the holy war against the enemy and in support of Palestine."

"The strike was conducted while Hezbollah's senior chain of command were operating from the headquarters and advancing terrorist activities against the citizens of the State of Israel," it said.

Friday's airstrike on Dahiyeh shook Beirut. A security source in Lebanon said the attack — a quick succession of massively powerful blasts — had left a crater at least 20 metres deep.

It was followed on Saturday by further airstrikes on Dahiyeh and other parts of Lebanon. Huge explosions lit up the night sky and more strikes hit the area in the morning. Smoke rose over the city.

Residents have fled Dahiyeh, seeking shelter in downtown Beirut and other parts of the city.

The fighting has prompted the Canadian government to book blocks of seats on commercial flights to help Canadians get out of Lebanon.

Those fleeing call strikes 'unbelievable'

"Yesterday's [Friday's] strikes were unbelievable. We had fled before and then went back to our homes, but then the bombing got more and more intense, so we came here, waiting for Netanyahu to stop the bombing," said Dalal Daher, speaking near Beirut's Martyrs Square, where some of the displaced were camping out.

She was referring to Israeli Prime Minister Benjamin Netanyahu.

Hezbollah also continued its cross-border rocket fire, setting off sirens and sending residents running for shelter deep inside Israel. Israeli missile defences blocked some of them and there was no immediate report of injuries.

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The escalation has increased fears the conflict could spin out of control, potentially drawing in Iran, Hezbollah's principal backer, as well as the United States.

Israel demands that Hezbollah move its fighters and weapons from a border area close to northern Israel in order to protect more than 60,000 Israeli who live there, and allow them to return to their communities.

Hezbollah began launching rockets into northern Israel after Hamas's Oct. 7 attack on southern Israel triggered the war in Gaza. Both Hamas and Hezbollah, which says it's showing solidarity with Palestinians in Gaza, are backed by Iran's regime. Hezbollah has a presence in both the Lebanese parliament and government.

Israeli air force patrolling near Beirut airport

Lebanon's Transport and Public Works Ministry asked an Iranian plane not to enter Lebanese airspace after Israel warned on Friday air traffic control at the Beirut airport that it would use "force" if the plane landed, a source at the Lebanese Transport Ministry told Reuters. The source said it was not clear what was on the plane, adding: "The priority is people."

Late on Friday, Rear Adm. Daniel Hagari, the Israeli military spokesperson, said its air force planes were "patrolling the area of the Beirut airport" and would not allow "hostile flights with weapons to land" there.

"We know about Iranian arms transfers to Hezbollah and are thwarting them," he said.

Hezbollah fires more rockets

Hezbollah has fired hundreds of rockets and missiles at targets in Israel, including Tel Aviv. The group said it had fired more on Saturday. Israel's air defence systems have ensured the damage has so far been minimal.

The Israeli military said the country is on high alert for a broader conflict and it hoped Nasrallah's reported death would cause the group to change course.

"We hope this will change Hezbollah's actions," Lt.-Col. Nadav Shoshani said in a media briefing. But he said it would still take time to degrade Hezbollah's capabilities.

"We've seen Hezbollah carry out attacks against us for a year. It's safe to assume that they are going to continue carrying out their attacks against us or try to," he said.

Hours before the latest barrage, Netanyahu told the United Nations that his country had a right to continue the campaign.

"As long as Hezbollah chooses the path of war, Israel has no choice, and Israel has every right to remove this threat and return our citizens to their homes safely," he said.

Evacuation warning

Lebanese health authorities confirmed six dead and 91 wounded in the initial attack on Friday — the fourth on Beirut's Hezbollah-controlled southern suburbs in a week and the heaviest since the 2006 war.

The toll appeared likely to rise much higher. There was no word on casualties from the later strikes. Israeli strikes have killed more than 700 people this past week, Lebanese authorities said.

Late on Friday, the Israeli military told residents in some parts of Dahiyeh to evacuate, saying it would target missile launchers and weapons storage sites it said were under civilian housing.

Hezbollah denied any weapons or arms depots were located in buildings that were hit in the Beirut suburbs, the group's media office said.

Alaa al-Din Saeed, a resident of a neighbourhood that Israel identified as a target, was fleeing with his wife and three children.

"We found out on the television. There was a huge commotion in the neighbourhood," he said. The family grabbed clothes, identification papers and some cash but were stuck in traffic with others trying to flee.

WATCH | Why Israel had been targeting Nasrallah: 

Israeli airstrikes target Hezbollah leader Hassan Nasrallah in major escalation

Israeli missile strikes targeting Hezbollah leader Hassan Nasrallah have flattened buildings in southern Beirut in the most powerful attacks of the conflict so far.

"We're going to the mountains. We'll see how to spend the night — and tomorrow we'll see what we can do."

The number of people in Lebanon displaced by the conflict now stands at well over 200,000.

Israel says its aim is to allow tens of thousands of residents evacuated from communities in northern Israel to return to their homes safely.

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