By Bassem Mroue

BEIRUT (AP) — The Israeli military said it struck Hezbollah’s headquarters in Beirut on Friday in a series of massive explosions that targeted the leader of the militant group and leveled multiple high-rise apartment buildings. The biggest blast to hit the Lebanese capital in the past year appeared likely to push the escalating conflict closer to full-fledged war. At least six people were killed and 91 were wounded, Lebanon’s health ministry said.

Hezbollah leader Hassan Nasrallah was the target of the strikes on the group’s headquarters, according to two people familiar with the matter who requested anonymity, including one U.S. 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.

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

Israeli army spokesman 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 Beirut’s Dahiyeh suburbs, according to Lebanon’s national news agency. A wall of billowing black and orange smoke rose into the sky as windows were rattled and houses shaken some 30 kilometers (18 miles) north of Beirut.

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

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 defense 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.