Hamas leader Ismail Haniyeh was assassinated in the early hours of the morning in Iran, the Palestinian militant group Hamas said on Wednesday, describing the strike as a “severe escalation” that would not achieve its goals.

Iran’s Revolutionary Guards confirmed the death of Haniyeh, hours after he attended a swearing in ceremony for the country’s new president, and said it was investigating.

There was no immediate comment from Israeli authorities.

The White House did not immediately respond to a request for comment on Haniyeh.

The news, which came less than 24 hours after Israel claimed to have killed the Hezbollah commander it said was behind a deadly strike in the Israeli-occupied Golan Heights, appears to set back chances of any imminent ceasefire agreement in Gaza.

“This assassination by the Israeli occupation of Brother Haniyeh is a grave escalation that aims to break the will of Hamas,” senior Hamas official Sami Abu Zuhri told Reuters.

He said Hamas would continue the path it was following, adding: “We are confident of victory.”

Assassinations and attempted assassinations

Palestinian leaders and operatives who were targeted by the most powerful and sophisticated military in the Middle East.

YAHYA AYYASH

Elusive Islamic militant mastermind behind a wave of Palestinian suicide bombings nicknamed “The Engineer”, was killed in then PLO-ruled Gaza. He died on January 5, 1996, when his cellular phone exploded in his hands. Palestinians blamed Israel, which declined to take responsibility. Hamas retaliated in four suicide attacks that killed 59 people in three Israeli cities over nine days in February and March.

KHALED MESHAAL

Former Hamas leader Khaled Meshaal became known around the world in 1997 after Israeli agents injected him with poison in a botched assassination attempt on a street outside his office in the Jordanian capital Amman.

The hit, ordered by Israeli Prime Minister Benjamin Netanyahu, so enraged Jordan’s then-King Hussein that he spoke of hanging the would-be killers and scrapping Jordan’s peace treaty with Israel unless the antidote was handed over.

Israel did so, and also agreed to free Hamas leader Sheikh Ahmed Yassin, only to assassinate him seven years later in Gaza.

AHMED YASSIN

Israel killed the quadriplegic co-founder and spiritual leader of Hamas, Sheikh Ahmed, in a helicopter missile strike on March 22, 2004 as he left a mosque in Gaza City. Israel attempted to kill him in 2003 while he was at the house of a Hamas member in Gaza.

Thousands of Palestinians marched in Gaza shouting calls of revenge and threatened to “send death to every home” in Israel.

His death led to widespread protests and condemnation from the Palestinian territories and the broader Muslim world marked a significant escalation in the Israeli-Palestinian conflict, underlining the deep-seated tensions and the challenges of achieving peace in the region.

ABDEL-AZIZ AL-RANTISI

An Israeli helicopter missile strike on a car in Gaza City killed Hamas leader Abdel-Aziz al-Rantissi on April 17, 2004. Two bodyguards were also killed. The Hamas leadership went into hiding and the identity of Rantissi’s successor was kept secret.

His assassination came shortly after he had taken over as Hamas leader in Gaza following the killing of Sheikh Ahmed Yassin.

ADNAN AL-GHOUL

Hamas master bomber was killed in an Israeli air strike in Gaza City on Oct. 21, 2004. Ghoul was number 2 in the military wing of Hamas and known as the “Father of the Qassam” rocket, a makeshift missile frequently fired into Israeli towns.

NIZAR RAYYAN

A cleric widely regarded as one of Hamas’s most hardline political leaders, had called for renewed suicide bombings inside Israel. Two of his four wives and seven of his children were also killed in the bombing in Jabalya refugee camp on January 1, 2009. Days later, an Israeli airstrike killed Hamas’s interior minister, Saeed Seyyam, in the Gaza Strip on January 15. Seyyam was in charge of 13,000 Hamas police and security men.

SALEH AL-AROURI

An Israli drone strike on Beirut’s southern suburbs of Dahiyeh killed Deputy Hamas chief Saleh al-Arouri on January 2, 2024. Arouri was also the founder of Hamas military wing, the Qassam Brigades.

ISMAIL HANIYEH

Haniyeh was assassinated in the early hours of Wednesday morning in Iran, the Palestinian militant group said.

Iran’s Revolutionary Guards confirmed the death of Haniyeh, hours after he attended a swearing-in ceremony for the country’s new president, and said it was investigating.

Iranian media reported that he was staying at “a special residence for war veterans in north Tehran” Iran’s NourNews said Haniyeh’s residence was hit by an airborne projectile.

Haniyeh, normally based in Qatar, has been the face of the Palestinian group’s international diplomacy as the war set off by the Hamas-led attack on Israel on Oct. 7 has raged in Gaza, where three of his sons were killed in an Israeli airstrike.

Appointed to the Hamas top job in 2017, Haniyeh has moved between Turkey and Qatar’s capital Doha, escaping the travel curbs of the blockaded Gaza Strip and enabling him to act as a negotiator in ceasefire talks or to talk to Hamas’ ally Iran.