A founding member of the Qassam Brigades, Hamas' military wing, established in the 1990s, he was code-named The Guest and led the Qassam Brigades for over two decades, becoming a key architect of its strategies and operations.

Israel’s military announced on Thursday that it had killed Hamas' top military commander, Mohammed Deif, in an airstrike in southern Gaza on July 13. The Palestinian group has yet to confirm his death.