Iran's supreme leader, Ayatollah Ali Khamenei, has promised 'harsh punishment' for Israel following the assassination of Hamas leader Ismail Haniyeh in Tehran on Wednesday. 'Through this act, the criminal and terrorist Zionist regime has set the stage for severe retribution, and it is our obligation to avenge his blood since he was martyred on the soil of the Islamic Republic of Iran,' Khamenei stated in a message released by the official news agency IRNA. Iran has declared a three-day period of mourning.

Khamenei also expressed in a statement on X, 'In response to this sorrowful, tragic incident that occurred within the borders of the Islamic Republic, it is our duty to exact revenge.' The Iran's Revolutionary Guards confirmed the incident, stating that Haniyeh's residence in Tehran was attacked, resulting in his death along with a bodyguard. Iranian media reported that the 2am (2230 GMT) attack targeted 'the special residences for war veterans in north Tehran' where Haniyeh was staying. Haniyeh had traveled to Tehran to participate in the swearing-in ceremony of President Masoud Pezeshkian on Tuesday. Pezeshkian pledged to make Israel 'regret' Haniyeh's killing, stating, 'The Islamic Republic of Iran will defend its territorial integrity, honor, pride, and dignity, and will make the terrorist invaders regret their cowardly action.'

An 'official and public' funeral for Haniyeh will be conducted in Tehran on Thursday, followed by his body being transported to Qatar for burial on Friday, according to Hamas. Palestinian President Mahmud Abbas denounced Haniyeh's killing as a 'cowardly act.' Palestinian factions in the Israeli-occupied West Bank have called for a general strike and protest marches throughout the territory.