Jerusalem: Israeli Prime Minister Benjamin Netanyahu said on Wednesday that Mohammad Sinwar, Hamas' Gaza chief and younger brother of the group’s deceased leader Yahya Sinwar, had been killed. Yahya was the mastermind behind the October 2023 attack.

Mohammad Sinwar had been the target of an Israeli strike on a hospital in southern Gaza earlier this month. Netanyahu said on May 21 that it was likely he was dead. On Wednesday, the Israeli leader announced in parliament that Sinwar had been "eliminated", as he listed other Hamas officials killed by Israel over the past 20 months, including Yahya Sinwar.

"In the last two days we have been in a dramatic turn towards a complete defeat of Hamas," Netanyahu said, adding that Israel was also "taking control of food distribution" — a reference to a new aid system in Gaza managed by a US-backed group. Israeli military chief Eyal Zamir said on May 26 that Hamas had lost key assets, including its command and control centre.

Hamas has yet to confirm Sinwar's death.

Who is Mohammad Sinwar?

Mohammad Sinwar rose to senior leadership after Israel killed his brother Yahya in combat last year. Yahya Sinwar, who orchestrated the October 2023 assault, was named Hamas' overall leader after the killing of Ismail Haniyeh in Iran. Israel later released footage of a severely wounded Yahya hurling a piece of wood at a hovering drone — his final act of defiance before death, and his brother’s rise.

If confirmed, Mohammad Sinwar's death would leave his associate Izz al-Din Haddad, who currently oversees operations in northern Gaza, in charge of Hamas' armed wing across the enclave. It remains unclear how Sinwar’s death might influence decision-making in the group — for example, whether it would shift more power to exiled members of Hamas’ leadership council during ceasefire negotiations.

Hamas officials describe Sinwar and Haddad as “ghosts” who have repeatedly eluded Israeli intelligence. Like Yahya, Mohammad survived numerous assassination attempts, including airstrikes and explosives, according to Hamas sources.

On one occasion, a remote-controlled explosive disguised as a brick was planted along his route to a cemetery. In 2003, Hamas operatives found a bomb embedded in the wall of his house, foiling another attempt blamed on Israeli intelligence.

Known for covert operations, Mohammad Sinwar played a central role in planning and executing the October 7 attack — widely seen as Israel’s worst security failure — according to Hamas sources.

He was also believed to be a key figure in the 2006 cross-border raid and abduction of Israeli soldier Gilad Shalit. Hamas held Shalit for five years before exchanging him for over 1,000 Palestinian prisoners. Among those released was Yahya Sinwar, whose meticulous planning for the 2023 assault shattered Israel’s image as an invulnerable power in the region.

Born on September 16, 1975, Mohammad Sinwar rarely appeared in public or spoke to the media. The Sinwars originated from Asqalan — now the Israeli city of Ashkelon — and, like hundreds of thousands of Palestinians during the 1948 war, became refugees. The family later settled in Khan Younis, now largely reduced to rubble.

Mohammad was educated in schools run by the UN’s Palestinian relief agency (UNRWA), which has had longstanding tensions with Israel, including during the current war. He joined Hamas shortly after its founding, inspired by his brother Yahya, a former member of the Muslim Brotherhood — the Middle East’s oldest and once most influential Islamist movement.

His reputation as a hardliner helped him ascend through the military ranks. By 2005, he was leading Hamas’ Khan Younis Brigade — one of its largest and most powerful units. The brigade has carried out cross-border raids, fired rockets, and planted explosives along the frontier. It also closely monitored Israeli troop movements. In 2006, elite fighters under Sinwar’s command took part in Shalit’s abduction. Sources close to Hamas say Sinwar developed strong ties with Marwan Issa, the military wing’s deputy commander, and Mohammed Deif, the reclusive military chief assassinated by Israel.

Background
Netanyahu has vowed to eliminate Hamas, and Israel's offensive — powered by the Middle East's most advanced military — has dealt the group severe blows. Yet Hamas, formed during the first Palestinian uprising in 1987 and responsible for suicide bombings, remains standing.

Netanyahu’s announcement comes as Israel intensifies its military campaign in Gaza after breaking a fragile ceasefire with Hamas in March. Israel has said its goal is to dismantle Hamas’ governing and military structures and secure the release of hostages still held in Gaza.

The war erupted on October 7, 2023, when Hamas-led militants stormed out of Gaza, killing around 1,200 people, mostly civilians, in southern Israeli communities. More than 250 were taken as hostages into Gaza.

Israel’s retaliatory assault has devastated the coastal territory, killing more than 53,000 people according to Gaza health officials, and displacing over 2 million Palestinians. Gaza health authorities say most of the dead are civilians but have not specified how many militants have been killed. Israel claims to have killed tens of thousands of fighters but has not provided evidence to back those claims.