GAZA STRIP, July 31 — Palestinian militant group Hamas said Wednesday that an Israeli strike in Tehran killed its chief Ismail Haniyeh.

"Brother, leader, mujahid Ismail Haniyeh, the head of the movement, died in a Zionist strike on his residence in Tehran after he participated in the inauguration of the new (Iranian) president,” the movement said in a statement.

A senior Hamas official said Wednesday that the killing of the Palestinian movement's chief Ismail Haniyeh "will not go unanswered".

"The assassination of leader Ismail Haniyeh is a cowardly act and will not go unanswered," Hamas political bureau member Musa Abu Marzuk said in a statement. — AFP