Israel's military said Thursday it had struck and killed a close adviser to Hezbollah chief Naim Qassem in Beirut a day earlier, when Israeli strikes pummelled Lebanon.

"Yesterday, the IDF struck in the Beirut area and eliminated Ali Yusuf Harshi, the personal secretary and nephew of Hezbollah Secretary-General Naim Qassem," a military statement said.

Harshi was "a close associate and personal adviser to ... Qassem and played a central role in managing and securing his office", it added.

Hezbollah entered the ​war ⁠in the region on Iran's side on March 2, two days after the United States and Israel began airstrikes against Iran, killing then Iranian Supreme Leader Ali Khamenei.

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 U.S.-backed cease-fire 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 U.S. proposal aimed at extending the cease-fire. 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 resistance 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 ​in Lebanon and backed by Iran's Revolutionary Guards to fight what was then the Israeli occupation of southern Lebanon.