The head of Hamas's military wing, Mohammed Deif, was killed in an Israeli airstrike in Gaza last month, the Israeli military said on Thursday, a day after a political leader from the militant group was assassinated in Tehran.

"The IDF [Israel Defence Forces] announces that on July 13th, 2024, IDF fighter jets struck in the area of Khan Younis, and following an intelligence assessment, it can be confirmed that Mohammed Deif was eliminated in the strike," the military said.

Israeli Defence Minister Yoav Gallant said Deif's death was a milestone in Israel's goal of destroying Hamas's military wing, known as Al-Qassam Brigades.

"Hamas is disintegrating," Gallant said on X. "Hamas terrorists may either surrender or they will be eliminated."

Hamas neither confirmed nor denied the killing of Deif, but one official, Ezzat Rashaq, said any word on deaths of its leaders was the responsibility of the group, as "no news published in the media or by any other parties can be confirmed."

The Israeli announcement came as crowds gathered in Tehran for the funeral procession of Hamas leader Ismail Haniyeh.

Iran and Hamas have blamed Haniyeh's killing on Israel, which has neither denied nor confirmed a role in the assassination. It did, however, confirm it killed a senior commander of the Lebanese Hezbollah movement in Beirut on Tuesday. Hezbollah chief Sayyed Hassan Nasrallah, speaking in a televised address on Thursday, promised a "real response, not a performative response," after the killing of Fuad Shukr.

Hezbollah and Hamas are backed by Iran. The latest killings have raised concern of a further escalation in hostilities in the Middle East, with threats of revenge against Israel, which has said it does not seek regional war but that it would respond forcefully to any attack.

Deif is believed to have been one of the masterminds of the Oct. 7 attack on southern Israel led by Hamas, which is considered a terrorist organization by many Western governments including Canada. The attacks sparked the Gaza war, now in its 300th day.

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One of Hamas's most dominant figures, Deif rose through the group's ranks over 30 years, developing its network of tunnels and its bomb-making expertise.

He has topped Israel's most wanted list for decades, held personally responsible for the deaths of dozens of Israelis in suicide bombings.

Wanted by the International Criminal Court

Deif, 58, had survived seven previous Israeli assassination attempts, the most recent in 2021. Hamas sources said Deif lost an eye and sustained serious injuries in one leg in one of Israel's past attempts to kill him. His survival over the years made him a folk hero for some Palestinians.

Deif rarely spoke and never appeared in public. There are only three images of Deif: one in his 20s, another of him masked, and an image of his shadow, which was used when an audio tape was broadcast on Oct. 7.

"Today the rage of Al-Aqsa, the rage of our people and nation is exploding," Deif said in the recording the day of the attacks.

Speaking in a calm voice, Deif said in his recording that Hamas had repeatedly warned Israel to stop crimes against Palestinians, to release prisoners and to halt its expropriation of Palestinian land. The group had now decided to "put an end to all this," he said.

In May 2024, the International Criminal Court's prosecutor said he had requested arrest warrants for Deif, Hamas political leader Yahya Sinwar and another Hamas figure over the attack, and for Prime Minister Benjamin Netanyahu and his defence chief over Israel's response.

Sinwar is still believed to be directing military operations, possibly from bunkers beneath Gaza, while playing a leading role in indirect negotiations with Israel for a prisoner swap deal.

Both Israel and Hamas dismissed the ICC accusations and said they objected to the way the announcement of the request on the same day appeared to equate them with each other — though they faced different charges.

Born as Mohammad Masri in 1965 in the Khan Younis refugee camp set up after the 1948 Arab-Israeli War, the militant leader became known as Mohammed Deif after joining Hamas during the first intifada, or Palestinian uprising, which began in 1987.

His wife, seven-month-old son, and three-year-old daughter were killed in an Israeli airstrike in 2014.

More than 39,480 Palestinians have been killed and 91,128 have been injured in the Israeli military offensive on Gaza since Oct. 7, the Gaza Health Ministry said in a statement on Thursday. The ministry does not distinguish between combatants and civilians in its count.

The Oct. 7 attacks killed 1,200 people, including several Canadians, and took some 250 others hostage, according to Israeli government tallies. More than 100 hostages were repatriated in late 2023, but about 110 hostages remain unaccounted for, with the Israeli government believing about one-third are no longer alive.