The Israel Defense Forces (IDF) confirmed on Thursday that Yahya Sinwar, the mastermind behind the Oct. 7 attacks, was killed in an airstrike in southern Gaza after evading Israeli forces for over a year.

The military announced on X, “Eliminated: Yahya Sinwar.” Reports initially surfaced earlier in the day that a terrorist resembling the Hamas leader was killed in a recent airstrike near Rafah, with the IDF subsequently confirming the details.

Intelligence officials had speculated that Sinwar might use hostages as human shields, but the IDF confirmed that no hostages were harmed in the strike that killed Sinwar.

Israeli Prime Minister Benjamin Netanyahu and his cabinet had vowed to track down and eliminate Sinwar after discovering he orchestrated the Oct. 7 massacre that claimed over 1,200 lives in Israel and resulted in 251 kidnappings. Just days after the attack, Sinwar was seen escaping with his family into Hamas’ underground tunnel system, managing to evade IDF detection for more than a year.

Sinwar, who had been Hamas’ Gaza chief since 2017, ascended to the top of the terror group after the assassination of its former leader, Ismail Haniyeh, in Tehran in July. Under Sinwar’s leadership, cease-fire negotiations between Hamas and Israel stalled as he opposed any end to the conflict.

Describing the deaths of Palestinians in Gaza as “necessary sacrifices,” Sinwar repeatedly obstructed hostage negotiations, urging Hamas to avoid compromise, claiming they were on the verge of eliminating the Jewish state. Even among his peers, Sinwar was seen as a “megalomaniac,” hindering Hamas’ political leaders’ efforts to legitimize a Palestinian state, according to the Wall Street Journal.

However, Sinwar had the support of Hamas’ rank-and-file, who respected him for the 22 years he spent in Israeli prisons before his release in 2011. Known as the “Butcher of Khan Younis,” Sinwar instilled fear by hunting down and murdering Palestinians suspected of collaborating with Israel.

The question of who will replace Sinwar as Hamas’ de facto leader remains unanswered. With Sinwar gone, the families of the remaining 97 hostages are urging Israel to propose a new cease-fire agreement, as reported by the Times of Israel.

“We have settled the score with the arch-murderer Sinwar, but now, more than ever, the lives of my son Matan and the other hostages are in tangible danger,” wrote Einav Zangauker to Netanyahu. “There will be no real closure, no total victory if we don’t save their lives and bring them all back,” she added.