"Brother, leader, mujahid Ismail Haniyeh, the head of the movement, died in a Zionist strike on his headquarters in Tehran after he participated in the inauguration of the new (Iranian) president," Hamas said in a statement.
Iran’s Revolutionary Guard Corps (IRGC) announced Haniyeh’s death, saying that it occurred at his Tehran residence, where a bodyguard was also killed.
"The residence of Ismail Haniyeh, head of the political office of Hamas Islamic Resistance, was hit in Tehran, and as a result of this incident, he and one of his bodyguards were martyred," the IRGC said in a statement.
Iranian media reported that the Palestinian leader was killed at around 2 am local time on Wednesday.
Haniyeh was among the world leaders and officials who attended the inauguration of Iran’s new President Masoud Pezeshkian on Tuesday.
Israel did comment on the strike as of publication.
Senior Hamas officials said that the killing of Haniyeh will not go “unanswered.”
“The assassination of leader Ismail Haniyeh is a cowardly act and will not go unanswered," Hamas political bureau member Musa Abu Marzuk said in a statement.
Haniyeh was elected Hamas bureau chief in 2017, succeeding Khaled Mashaal. He became the Palestinian prime minister in 2006 following an upset victory in that year’s parliamentary elections against rival Fatah.
The killing of Haniyeh comes against the backdrop of soaring tensions between Israel and Iran-backed groups in the Middle East.
The Israeli army announced on Tuesday that it killed Fuad Shukr (also known as Sayyid Mushan), the right hand man of Lebanese Hezbollah leader Hassan Nasrallah, and the group’s senior military commander in an airstrike targeting the Lebanese capital of Beirut.
International condemnation
The killing of Haniyeh drew waves of international and regional condemnation.
Palestinian President Mahmoud Abbas on Wednesday slammed the killing, labeling it a “cowardly act” while urging Palestinians to remain united against Israel.
"President Mahmud Abbas of the State of Palestine strongly condemned the assassination of Hamas leader Ismail Haniyeh, deeming it a cowardly act and a serious escalation," his office said in a statement.
Iran’s foreign ministry condemned the killing of the Hamas leader, state media IRNA reported, vowing retaliation.
“The pure blood of this steadfast fighter, who spent his life in honorable struggle and resistance against the usurping Zionist regime and in the path of liberating the noble Al-Quds, will never be in vain," IRNA quoted FM Nasser Kanaani as saying.
The Turkish foreign ministry also condemned the “shameful assassination” of Haniyeh, who is also an ally of President Recep Tayyip Erdogan.
"We condemn the assassination of the leader of Hamas's political office, Ismail Haniyeh, in a shameful assassination in Tehran," the ministry said in a statement, warning that the killing “aims to spread the Gaza war to a regional dimension.”
Russia denounced the killing of Haniyeh on Wednesday labeling it an “unacceptable political assassination.”
"It is a completely unacceptable political assassination, and this will lead to a further escalation of tensions," Russian Deputy Minister of Foreign Affairs Mikhail Bogdanov told the state-run RIA Novosti news agency.
