Iran's Revolutionary Guard said a short-range projectile was behind the killing of Hamas political chief Ismail Haniyeh and accused the United States of supporting the attack which it blamed on Israel, state TV reported on Saturday.

The televised statement said a rocket with a seven-kilogram (about 15-pound) warhead was used to target the residence of Hamas' political in the capital Tehran on Wednesday, adding it caused heavy devastation, but didn't share details of the location.

Haniyeh was in Iran to attend the inauguration ceremony of the newly elected Iranian President Masoud Pezeshkian.

“The action was designed and carried out by the Zionist regime and supported by the US,” said the Guard's statement and reiterated a call for retaliation.

“The warmongering and terrorist Zionist regime will receive harsh punishment in the suitable time, place, and capacity," it added.

Israel had pledged to kill Haniyeh and other Hamas leaders over the group's October 7 attack on southern Israel that sparked the war in Gaza.

The assassination has sparked fears of pushing the region into a wider conflict and forcing Iran and Israel into a direct confrontation if Iran retaliates.

In April, Iran launched hundreds of missiles and drones at Israel which the Jewish state said it intercepted 99 per cent of. It came less than two weeks after a suspected Israeli strike in Syria killed two Iranian generals, marking the first time Iran has launched a direct military assault on Israel, despite decades of enmity dating back to the country's 1979 Islamic Revolution.

Iran does not recognise Israel and supports anti-Israeli militant groups like Hamas and Lebanese Hezbollah.