A deadly Israeli airstrike on Hezbollah’s stronghold in southern Beirut on Friday has left over a dozen people dead, including a high-ranking Hezbollah commander, sharply escalating the conflict between the two sides and raising fears of all-out war.

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.