The attack represents another security failure for the militant group that has been reeling from repeated Israeli blows.

Hezbollah did not immediately confirm the death of Ibrahim Aqeel. The United States had accused him of being involved in bombings that killed more than 200 U.S. Marines and many others in Beirut in 1983.

Israel launched an airstrike on a southern suburb of Beirut, hours after Hezbollah fired 140 rockets into northern Israel. The escalation marks one of the more intense exchanges between Israel and the Lebanese militant group in recent weeks,