Hamas has named Yahya Sinwar, its top leader in Gaza who masterminded the deadly Oct. 7 attack on Israel, as its new leader after his predecessor was killed during an airstrike in Iran. 

The move is certain to provoke Israel, which has put him at the top of its kill list after the Oct. 7 attack in which militants killed 1,200 people in southern Israel and took about 250 as hostages.

In a statement, Hamas announced ‘the selection of Commander Yahya Sinwar as head of the movement’s political bureau, succeeding the martyred leader Ismail Haniyeh, may God have mercy on him.’

Sinwar is close to Iran and has worked over the years to build up the strength of Hamas. His promotion came after the death of Ismail Haniyeh. Haniyeh was killed in an apparent bombing in Tehran, while a top Hezbollah commander was also killed in Beirut last week in a presumed Israeli strike.

The killings have raised fears of a wider conflict that could see Israel fighting on multiple fronts. 

Iran has vowed to retaliate. Israel has accused Sinwar of masterminding the deadly Oct. 7 attack. Israeli officials believe he has taken refuge in the terror group’s vast network of tunnels in the Gaza Strip and is surrounded by hostages as human shields. 

Last week, Israel said it had confirmed the death of the head of Hamas’ military wing, Mohammed Deif, in a July airstrike in Gaza. Hamas has not confirmed his death.

Hamas’ representative in Iran, Khaled Kaddoumi, called Sinwar a ‘consensus choice’ popular among all factions and involved in the group’s decision-making throughout, including in negotiations. In a voice message to the Associated Press, he said Sinwar knows the political aspirations of the Palestinians for a state and the return of refugees but is also a ‘fierce fighter on the battlefield.’

Secretary of State Antony Blinken said Sinwar ‘has been and remains the primary decider when it comes to concluding the cease-fire.’

He said Sinwar must ‘decide whether to move forward with a cease-fire that manifestly will help so many Palestinians in desperate need, women, children, men who are caught in a crossfire. … It really is on him.’

Sinwar has been Hamas’ leader inside Gaza since 2017, ruling with an iron grip.

In May, the International Criminal Court sought an arrest warrant against Sinwar on charges of war crimes over the Oct. 7 attack, as well as against Israeli Prime Minister Benjamin Netanyahu and Israel’s defense minister for war crimes.

The Associated Press contributed to this report.