Iran vows revenge after Hamas leader is killed, Netanyahu warns of 'heavy price' against aggression

Hamas' top political leader was killed Wednesday by a predawn airstrike in the Iranian capital, Iran and the militant group said, blaming Israel for a shock assassination that risked escalating into an all-out regional war. Iran's supreme leader vowed revenge against Israel.

Hamas' top political leader was killed Wednesday by a predawn airstrike in the Iranian capital, Iran and the militant group said, blaming Israel for a shock assassination that risked escalating into an all-out regional war. Iran's supreme leader vowed revenge against Israel.

Israeli Prime Minister Benjamin Netanyahu said Israel "will exact a very heavy price from any aggression against us on any front" but did not mention the killing. "There are challenging days ahead," he added.

Israel had pledged to kill Ismail Haniyeh and other Hamas leaders over the group's Oct. 7 attack on southern Israel that sparked the war in Gaza. The strike came just after Haniyeh had attended the inauguration of Iran's new president in Tehran — and hours after Israel targeted a top commander in Iran's ally Hezbollah in the Lebanese capital, Beirut.

The assassination was potentially explosive amid the region's volatile, intertwined conflicts because of its target, its timing and the decision to carry it out in Tehran. Most dangerous was the potential to push Iran and Israel into direct confrontation if Iran retaliates. The U.S. and other nations scrambled to prevent a wider, deadlier conflict.

In a statement on his official website, Iranian supreme leader Ayatollah Ali Khamenei said revenge was "our duty" and that Israel had "prepared a harsh punishment for itself" by killing "a dear guest in our home."

Bitter regional rivals, Israel and Iran risked plunging into war earlier this year when Israel hit Iran's embassy in Damascus in April. Iran retaliated, and Israel countered in an unprecedented exchange of strikes on each other's soil, but international efforts succeeded in containing that cycle before it spun out of control.

Haniyeh's killing also could prompt Hamas to pull out of negotiations for a ceasefire and hostage release deal in the 10-month-old war in Gaza, which U.S. mediators had said were making progress.