His death, if confirmed by Hezbollah, deals another big blow to the armed group and to Tehran as it is one of Iran’s main allies in the Middle East.

By attacking Israel on March 2, Hezbollah entered the war in the region on Iran’s side, two days after the United States and Israel began airstrikes against Iran.

Hezbollah attacked Israel after Iranian Supreme Leader Ali Khamenei was killed on the first day of the war. Israel said it would respond forcefully and has since carried out airstrikes that have killed more than a thousand people.

Israel had already weakened the group’s military capabilities and hammered it with a series of assassinations since the Gaza war began on Oct 7, 2023.

Despite a US-backed ceasefire between Israel and Lebanon in 2024 after more than a year of fighting, Israel has carried out regular strikes against what it has identified as Hezbollah targets in Lebanon. It accused the group of seeking to rearm.

Hezbollah refused to disarm under a US proposal aimed at extending the ceasefire. Qassem threatened Israel directly, saying missiles would fall on it if it resumed a broad war on Lebanon.

In 2024, Israel killed Qassem’s predecessor, veteran leader Hassan Nasrallah, in an airstrike on a Beirut suburb, the climax of a conflict that began when Hezbollah fired at Israeli positions at the border in support of the Palestinian Islamist militant group Hamas.

Hezbollah named Qassem, who had been a senior figure in the group for more than 30 years, as its new chief a month after Nasrallah’s killing.

The group was created in 1982 by Muslim Shiite militants in Lebanon and backed by Iran’s Revolutionary Guards to fight what was then the Israeli occupation of southern Lebanon.