Ismail Haniyeh, a senior Hamas leader, has been killed in an Israeli strike in Tehran, according to Iran’s Revolutionary Guards.
Both the IRGC and Hamas have said they blame Israel for the attack.
Haniyeh was in Tehran to attend Iranian President Masoud Pezeshkian’s swearing-in ceremony on Tuesday.
Iran gave no details on how Haniyeh was killed, and the Revolutionary Guard said the attack was under investigation.
Haniyeh left the Gaza Strip in 2019 and had lived in exile in Qatar.
Israel has vowed to kill Haniyeh and other leaders of Hamas over the group’s October 7 attack on Israel that killed 1,200 people and saw some 250 others taken hostage.
The top Hamas leader in Gaza is Yehya Sinwar, who masterminded the October 7 attack.
Iran’s statement gave no details on how Haniyeh was killed.
Iranian state television reported on his death early on Wednesday, and analysts immediately began blaming Israel for the attack.
Israel itself did not immediately comment but it often does not when it comes to assassination carried out by their Mossad intelligence agency.
Israel is suspected of running a years-long assassination campaign targeting Iranian nuclear scientists and others associated with its atomic programme.
In its campaign since, Israel has killed more than 39,360 Palestinians and wounded more than 90,900, according to the Gaza Health Ministry, whose count does not differentiate between civilians and combatants.