BEIRUT — The Israeli military said Friday that it struck the headquarters of Hezbollah in Beirut, where a series of massive explosions leveled multiple buildings and sent clouds of orange and black smoke into the sky in the biggest blasts to hit the Lebanese capital in the past year.

At least two people were killed and dozens were wounded, Lebanon’s health ministry said.

Three major Israeli TV channels said Hezbollah leader Hassan Nasrallah was the target of the strikes in Beirut’s southern suburbs. The reports could not be confirmed by The Associated Press, and the army declined comment. But given the size and timing of the blasts, there were strong indications that a senior leader may have been inside the buildings struck.

In a possible further sign of the strikes’ significance, Prime Minister Benjamin Netanyahu cut short a visit to the United States and was returning home instead of waiting until the end of Sabbath on Saturday evening, his office said. Israeli politicians do not normally travel on the Sabbath except for matters of great importance.

Hours earlier, Netanyahu addressed the U.N., vowing that Israel’s campaign against Hezbollah would continue — further dimming hopes for an internationally backed cease-fire. News of the blasts then came as Netanyahu was briefing reporters traveling with him. A military aide whispered into his ear, and Netanyahu quickly ended the briefing.

To a degree unseen in past conflicts, Israel this past week has aimed to eliminate Hezbollah’s senior leadership.

Israeli army spokesman Rear Adm. Daniel Hagari said the strikes targeted the main Hezbollah headquarters, located beneath residential buildings. Defense Minister Yoav Gallant’s office said he was huddling with the head of Israel’s air force and other top commanders at military headquarters, following updates.

The series of blasts reduced six buildings to rubble in the Haret Hreik neighborhood of Beirut’s Dahiyeh suburbs, according to Lebanon’s national news agency. The shock wave rattled windows and shook houses some 18 miles north of Beirut.

TV footage showed several craters amid collapsed buildings in the densely populated, predominantly Shiite neighborhood.

First responders were still searching under the rubble hours later as others struggled to put out fires. The full scope of casualties was not clear, the health ministry said, adding that 15 of the 76 wounded had been hospitalized. Many people who live in the vicinity were seen gathering belongings and fleeing along a main road out of the district.

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 had not been publicly known as Hezbollah’s main headquarters, though it is located in the group’s “security quarters,” a heavily guarded part of Haret Hreik where it has offices and runs several nearby hospitals.

The Pentagon said the U.S. had no advance warning of the strikes.

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 scope of Israel’s 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.

Israel’s strikes this week have 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 hit a home, killing nine members of the same family, the state news agency said.

At the U.N., Netanyahu 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 a possible war against Hezbollah would not last as long as the current war in Gaza because the Israeli military’s 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 with Israel — “not a high bar like Gaza” in terms of operational objectives, said the official, who spoke on the condition of anonymity.

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

Hussein Fadlallah, Hezbollah’s top official in Beirut, said in a speech that no matter how many commanders Israel kills, the group has endless numbers of experienced fighters who are deployed all over the front lines. Fadlallah 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.”