Tehran: Iran’s paramilitary Revolutionary Guard said Hamas leader Ismail Haniyeh was assassinated in Tehran.

No one immediately claimed responsibility for the assassination but suspicion immediately fell on Israel, which has vowed to kill Haniyeh and other leaders of Hamas over the group’s October 7 attack on Israel that killed 1200 people and saw some 250 others taken hostage.

Haniyeh was in Tehran to attend Iran’s President Masoud Pezeshkian’s swear-in ceremony. Iran gave no details on how Haniyeh was killed, and the Guard said the attack was under investigation.

No one immediately claimed responsibility for the assassination but suspicion immediately fell on Israel, which has vowed to kill Haniyeh and other leaders of Hamas over the group’s October 7 attack on Israel that killed 1200 people and saw some 250 others taken hostage.

In a statement, Hamas mourned the death of Haniyeh, who it said was killed in “a treacherous Zionist raid on his residence in Tehran”.

Israeli airstrikes killed three of his sons in April. Hamas said four of the leader’s grandchildren were also killed at that time.

Israel said they were Hamas operatives, and Haniyeh at the time accused Israel of acting in “the spirit of revenge and murder”.

There was no immediate reaction from the White House. The apparent assassination comes at a precarious time, as the Biden administration has tried to push Hamas and Israel to agree to at least a temporary ceasefire and hostage-release deal.

CIA Director Bill Burns was in Rome on Sunday to meet with senior Israel, Qatari and Egyptian officials in the latest round of talks. Separately, Brett McGurk, the White House Coordinator for the Middle East and North Africa, is in the region for talks with US partners.