Israel says it killed Hamas leader and October 7 mastermind Yahya Sinwar

• The Israeli military said Thursday it killed Hamas' leader, Yahya Sinwar, in an operation in Gaza.
• He was the architect of the October 7, 2023, attacks and a top target for Israel.
• Sinwar, 61, had been the leader of Hamas in Gaza since 2017.

The Israeli military said Thursday that it killed Hamas' leader, Yahya Sinwar, during an operation in Gaza, eliminating the architect of the October 7, 2023, massacre.

The Israel Defense Forces released a statement confirming that soldiers from its 828th Brigade killed Sinwar in southern Gaza on Wednesday.

"Sinwar was eliminated after hiding for the past year behind the civilian population of Gaza, both above and below ground in Hamas tunnels in the Gaza Strip," the IDF said.

"The dozens of operations carried out by the IDF and the ISA over the last year, and in recent weeks in the area where he was eliminated, restricted Yahya Sinwar's operational movement as he was pursued by the forces and led to his elimination," the military added.

Earlier on Thursday, the IDF said it was checking the possibility that it had killed Sinwar along with two unnamed "terrorists" but could not confirm whether it had done so. It said there were no signs that any hostages who were abducted on October 7 and taken to Gaza were present in the area.

Sinwar's death is a significant turning point for Israel and its yearlong war to eradicate Hamas. The Israeli government, with US support, had made it a key objective to kill him following the October 7 attacks, which left 1,200 people dead and triggered the war in Gaza and wider hostilities across the Middle East.

Despite months of intense Israeli air and ground operations that have leveled much of Gaza, Sinwar managed to remain elusive . Israel's military has used heavy weapons, including 2,000-pound bunker-buster bombs, to collapse Hamas' sprawling tunnel network under Gaza, where he was believed to be hiding.

"Our enemies cannot hide. We will pursue and eliminate them," Yoav Gallant, Israel's defense minister, wrote in a social-media post after the IDF first said that it was checking to see whether Sinwar was dead.

"No terrorist is immune to the long arm of the IDF," Danny Danon, Israel's ambassador to the United Nations, wrote on social media after the news of Sinwar's death was confirmed.

The conflict had been at an impasse, with Sinwar missing and Hamas — under his authority — rejecting cease-fire talks. In the meantime, Israel's military opened a northern front with a ground invasion into southern Lebanon to end attacks by Hezbollah.

Israel's devastating Gaza war has left over 40,000 Palestinians dead — most of them civilians, local health officials have said. And there are dire warnings that the humanitarian crisis is worsening amid the fighting.

It is unclear what implications Sinwar's killing could have on the war or the fate of about 100 hostages who are still being held in Gaza.

Avi Melamed, a former Israeli intelligence official, told Business Insider that Sinwar was the major obstacle preventing a hostage deal and that his killing could open the door for pressure toward some sort of agreement.

"Sinwar was the one that, to a large extent, was holding both Hezbollah and Iran hostages because of his refusal to move forward with a deal that could have led to a cease-fire in Gaza," Melamed, the founder of the Inside the Middle East institute, said.

The 61-year-old Sinwar had been the leader of Hamas in Gaza since 2017 and assumed leadership of its political wing following the July assassination of Ismail Haniyeh .

Meanwhile, the killing of Sinwar comes after Israel took out most of Hezbollah's leadership in Lebanon, including its longtime leader, Hassan Nasrallah , and amid heightened tensions with Iran , which supports both Hezbollah and Hamas.