Israel was still holding off on Monday from confirming that it had assassinated  Mohammed Deif, the shadowy commander of Hamas’ military wing, the Izzedine al-Qassam Brigades, who had survived multiple Israeli attempts on his life over the past two decades, prior to Israel’s targeted attack against him in Khan Yunis in the Gaza Strip on Saturday.

On Sunday, a Hamas official told French news agency AFP that Deif, who is referred to in Israel as the “cat with nine lives,” was “fine” after the attack. But Hamas provided no proof that Deif survived, and Israeli media reported on Monday that Deif’s body may be under heavy guard at a Gaza hospital.

There were also mixed reports that the airstrike, which Hamas officials said some 90 other people, including civilians, had halted hostage deal negotiations. AFP quoted Hamas officials as saying Israel’s actions had derailed the talks, which last week had begun to show signs of progress, but Hamas denied those claims, with Israeli media reporting that they would continue.

A security official who discussed the operational aspects of the strike detailed for JI the factors that went into the operation: the potential risk that a strike would pose for hostages that might be in the vicinity, the effect of the strike on ongoing cease-fire negotiations and casualties associated with the strike.

There was “sufficient and significant intelligence” indicating that no hostages were in the area of the strike, the official said. A “majority” of those killed in the strike — roughly 90 people — were of adult age, and are believed by the IDF to have been “affiliated in one way or another with Hamas.” The official noted that the IDF did not believe that the strike would significantly impact cease-fire negotiations, pointing out that “only military pressure brings Hamas to the negotiation table. Only military pressure brought about the first agreement” in November 2023 that secured the release of 100 hostages.

“We will continue to target senior Hamas leadership while also trying to achieve an agreement,” the official told JI. “We don’t see things as contradictory.”

The official confirmed that Hamas Commander Rafa’a Salameh, who oversaw the Khan Younis battalion and was believed to be with Deif at the time of the strike, was killed, which the official said was a significant step toward “destroying [Hamas’s] capability to function as an organized military framework.” 

While there is still no final confirmation of Deif’s death – with some speculating that he could have succeeded in escaping yet again by ducking into the vast subterranean tunnel system that still exists in some parts of the Gaza Strip – the elimination of such a senior leader would deal a serious blow to the Palestinian terror group that has been battling Israel since last October.

Long considered by Israel to be a top target in Gaza, Deif, 58, is viewed as just as senior and as influential as Hamas’ top leader in the Strip, Yahya Sinwar.

An elusive figure, he has served as commander of the Izzedine al-Qassam Brigades since 2002. Israeli military and intelligence officials believe that Deif, a skilled and experienced bomb maker, played an instrumental role in developing Hamas’ military capabilities, helping to build up the terror group’s rocket arsenal and design its vast subterranean tunnel system that snakes beneath the Gaza Strip.

Deif is also believed to be the key mastermind behind the brutal Oct. 7 massacre, with reports suggesting that he had been planning the surprise mass attack for two years.

Israel has attempted to assassinate him several times in the past, but Deif, who is a former actor and a master of disguise, has – so far – managed to outwit and survive those attempts.

In one assassination attempt in 2006, however, Deif was seriously injured, losing an eye and an arm. Some reports suggest that he has been reliant on a wheelchair. Another attempt in 2014, killed his wife, 7-month-old son and 3-year-old daughter.

Due to the attempts on his life, Israel’s archenemy keeps a low profile, rarely making public appearances. Until this year, the only known photo of him was from at least three decades ago. The photo that surfaced in January was reportedly obtained by Israeli forces fighting in the Gaza Strip and, according to Israeli media, dates back to 2018. It shows a man in a wooded area with one eye closed. 

Born as Mohammad Masri in the Khan Younis refugee camp in 1965, Deif was drawn to religion from an early age, first joining the Muslim Brotherhood before becoming a member of Hamas in 1987, Lt. Col. (res) Shaul Bartal, a senior researcher at the Begin-Sadat Center for Strategic Studies at Bar-Ilan University, told Jewish Insider.

According to reports, Deif, who studied physics, chemistry and biology at the Islamic University in Gaza, also headed the university’s entertainment committee and performed onstage in comedies. Some say the name Deif, which means “guest” in Arabic, came out of one of the roles he played during his college years; others say it is derived from his strategy of staying in a different location every night as a precaution against assassination attempts.

In 1989, Deif was captured by Israel and sentenced to 16 months in prison for his involvement in Hamas’ terror activities. After his release, he became further involved in Hamas’ military operations, said Bartal, noting that he was the protégé of Yahya Ayyash, dubbed “the Engineer” by Israel, who was assassinated in 1996.

Even though Israel had success in eliminating other Hamas military leaders, including Deif’s predecessor, Salah Shehadeh, Deif has managed to defy all attempts on his life, rising up through the ranks of the terror organization to head its military wing, said Bartal.

“He is a venerated figure among the Palestinian people and within Hamas” due to his vast experience in abducting Israeli soldiers and organizing multiple suicide attacks in Israel since 1995, Bartal added.   JI’s Melissa Weiss contributed to this report.