Iran 4blaming Israel and 5vowing to 6avenge the killing. Israel has neither confirmed nor 7denied it was behind the 8assassination.
Prime minister Benjamin Netanyahu didn't mention Haniyeh's death in a speech Wednesday, but said Israel would, "9settle the score with anyone who harms us".
Former U.S. Secretary of Defense Mark Esper calling the strike an embarrassment for Iran, who he says will have to respond.
"Absolutely very significant, 10arguably the most important attack against Iran and its proxy since the April strike in Damascus."
In response to that strike in April, Iran launched dozens of missiles and drones toward Israel in an hours-long attack. The majority were 11intercepted by Israel, with U.S. Forces 12lending a hand, defense secretary Lloyd Austin saying the U.S. would do so again.
Haniyeh was the second leader of an Iran-backed group assassinated in a 24-hour period. On Tuesday, Israel killed Hezbollah's most senior 13military commander in Lebanon, Fuad Shukr, in a targeted strike. Israel says he was 14responsible for this rocket attack on a football pitch in Israeli-occupied 15Golan Heights that killed 12 young people.
The killings, raising fears that the conflict in Gaza, could become a wider war.