Safieddine is a cousin of former Hezbollah General Secretary Hassan Nasrallah, who was assassinated in an Israeli airstrike late last month. The former had been viewed as one of the leading successors to Nasrallah since the 1990s and would often fill in for him when the former leader was out of the country.

“The IDF can now confirm that Hashem Safieddine, Head of the Hezbollah Executive Council, and Ali Hussein Hazima, Commander of Hezbollah’s Intelligence Headquarters, were eliminated by the IDF, along with additional Hezbollah commanders,” the Israel Defense Forces said in a statement. “The terrorists were eliminated in a strike carried out approximately three weeks ago in the area of Dahieh, a key Hezbollah terrorist stronghold in Beirut.”

The statement also said the Israeli Air Force “conducted a precise, intelligence-based strike on Hezbollah’s main intelligence headquarters, deliberately located underground beneath the civilian population in the Dahieh,” and that 25 Hezbollah members were in the headquarters when it was struck.

Videos of the attack showed a massive airstrike reminiscent of the strike that killed Nasrallah, featuring over a dozen explosions and a massive fireball.

Hezbollah has remained quiet about the attack. The Hezbollah-owned news station Al Manar carried on reporting as usual of fighting in southern Lebanon, according to the New York Times.

Safieddine had previously been thought to have been killed earlier this month after he went radio silent in the aftermath of another Israeli strike in Beirut. Israel’s Tuesday statement confirmed the speculation.

Hezbollah, perhaps the world’s most powerful paramilitary organization, has taken a severe beating over the past month, including a devastating pager and walkie-talkie explosion attack and the assassination of nearly its entire senior command. Hezbollah still hasn’t announced a new leader following the death of Nasrallah, with the matter of succession now set to be more complicated with Safieddine’s death.

Despite taking a battering, Hezbollah remains a capable organization, with tens of thousands of fighters, a vast tunnel network throughout southern Lebanon, and a vast missile arsenal of tens of thousands of rockets. Its attacks against Israel have grown increasingly bold in recent days, including a drone attack against one of Israeli Prime Minister Benjamin Netanyahu’s residences.