Def was born Mohammed Masri in 1965 in the Khan Younis refugee camp set up after the 1948 Arab-Israeli war.

Israel's military confirmed Thursday that Hamas' top military commander, Mohammed Def, was killed in an Israeli airstrike in southern Gaza on July 13. “We can now confirm: Mohammed Def has been eliminated,” the Israeli military said.

Izzat al-Rashq, a member of Hamas, said the news of Def's killing was unconfirmed.

“Confirming or denying the martyrdom of any leader of Qassam is a matter for the leadership of the Qassam Brigades and the leadership of the movement,” he said in a telegram, referring to Hamas' military wing.

In commemoration, Israeli Defense Minister Yoav Galant called Def “Gaza's Osama bin Laden” and hailed his death as “an important step in the process of ending Hamas as a military and administrative authority in Gaza”.

“Hamas terrorists can either surrender or be eliminated. Israel's defense establishment will pursue Hamas terrorists – both the planners and perpetrators of the 07.10 massacre. We will not rest until this mission is accomplished,” he posted on X.

All you need to know about Deif:

• Def was one of the founders of the Kassam Brigade in the 1990s
• Deaf led the force for over 20 years.
• Def was born Mohammed Masri in 1965 in the Khan Younis refugee camp set up after the 1948 Arab-Israeli war.
• After joining Hamas during the First Intifada, or Palestinian uprising, which began in 1987, he became known as Mohammed Def.
• Deif developed the group's tunneling and bomb-making skills and topped Israel's most wanted list for decades.
• His wife, seven-month-old son and three-year-old daughter were killed in an Israeli airstrike in 2014.
• The Israeli military considered him part of a three-man military council planning the October 7 attack on southern Israel.
• In an audiotape broadcast the same day, Def called the attack the “Al-Aqsa Flood”, a retaliation for Israeli attacks on Jerusalem's Al-Aqsa Mosque, Islam's third holiest site.
• Netanyahu's government has promised to kill all three leaders: Yahya Sinwar, the leader of Hamas in Gaza; Def; and his deputy Marwan Issa, who was killed by Israel in March.