The Israeli military has said they killed Hassan Nasrallah, the leader of the Hezbollah militant political group, in an air strike in Beirut on Friday.

The military said the strike was carried out while the Hezbollah leadership was meeting at their headquarters in Dahiyeh.

Ali Karki, the commander of Hezbollah’s southern front, and additional commanders were also killed in the attack, the Israeli military said.

Mr Nasrallah has led Hezbollah for more than three decades but has been in hiding for years, rarely appearing in public. He regularly gave speeches but always by video from unknown locations.

Israel’s chief of staff Herzi Halevi said the elimination of Mr Nasrallah was “not the end of our toolbox”, indicating that more strikes were planned.

The Israeli military said it was mobilising additional reserve soldiers as tensions escalate with Lebanon, activating three battalions of reserve soldiers to serve across the country. The call comes after it sent two brigades to northern Israel earlier in the week to train for a possible ground invasion.

Nadav Shoshani, an army spokesman, said the air strike was based on years of tracking Mr Nasrallah along with “real-time intelligence” that made it viable. He said Mr Nasrallah’s death had been confirmed through various types of intelligence but declined to elaborate.

Smoke rises as a building collapses in Beirut’s southern suburbs
Smoke rises as a building collapses in Beirut’s southern suburbs (Hussein Malla/AP)

He said that Israel has inflicted heavy damage on Hezbollah’s capabilities over the past week by targeting a combination of immediate threats and strategic weapons, such as larger, guided missiles. But he said much of Hezbollah’s arsenal remains intact and that Israel would continue to target the group.

“This isn’t a threat that has gone away,” he said.

Mr Shoshani said it is “safe to assume” that Hezbollah will retaliate and that Israel is on “high readiness” but he said Israel hopes the blow to Hezbollah will change the course of the war.

“We hope this will change Hezbollah’s actions,” he said. “We have been looking for solutions, looking for a change in reality that will bring our civilians home,” referring to the approximately 60,000 Israelis who have been evacuated from their homes along the Lebanese border for almost a year.

Mr Shoshani declined to say what munitions were used in the strike or provide an estimate on civilian deaths in the strike, only saying that Israel takes measures to avoid civilians whenever possible and clears strikes ahead of time with intelligence and legal experts.

Smoke rises from destroyed buildings in Beirut’s southern suburbs on Saturday morning
Smoke rises from destroyed buildings in Beirut’s southern suburbs on Saturday morning (Hussein Malla/AP)

The Lebanese health ministry said six people were killed and 91 injured in the strikes on Friday, which levelled six apartment buildings.

Further strikes were carried out in Bekaa Valley in eastern Lebanon.

Hours before the strikes, Israeli Prime Minister Benjamin Netanyahu addressed the United Nations, vowing that his country’s campaign against Hezbollah would continue — further dimming hopes for an internationally backed cease-fire.

Mr Netanyahu abruptly cut his United States visit short and returned to Israel.

Israel Prime Minister Benjamin Netanyahu  holds up maps
Israel Prime Minister Benjamin Netanyahu addresses the 79th session of the United Nations General Assembly on Friday (Richard Drew/AP)

Iran’s supreme leader has urged all Muslims to stand by Hezbollah but has not indicated how Tehran will respond to the reported killing of Mr Nasrallah.

Supreme Leader Ayatollah Ali Khamenei said “it is the duty of all Muslims to stand by the people of Lebanon and Hezbollah” against the “occupier, evil and suppressor” regime of Israel.

In a statement read on state TV, he said “all regional resistance forces” support and stand beside Hezbollah.

Iran’s influential parliamentary committee on national security met on Saturday and demanded a “strong” response against Israel, state TV reported.

More than 720 people have been killed in Lebanon since the conflict escalated on Monday, according to Lebanon’s health ministry.

The United Nations says the number displaced by the conflict from southern Lebanon has more than doubled, with more than 211,000 people affected.

Hezbollah began firing rockets into northern Israel in support of Hamas after it stormed into Israel on October 7, sparking the Israel-Hamas war.

Top Israeli officials have threatened to repeat the destruction of Gaza in Lebanon if the Hezbollah fire continues, raising fears that Israel’s actions in Gaza since October 7 would be repeated in Lebanon.

On Saturday, the Israeli military said it was mobilising additional reserve soldiers as tensions escalated.

Three further battalions of reserve soldiers were activated, following the sending of two brigades to northern Israel earlier in the week to train for a possible ground invasion.