One of the founders of Hamas, who was also one of the planners of its onslaught of October 7, 2023, was killed in an airstrike in Gaza City on Friday night, the Israel Defense Forces announced Saturday.

Hakem al-Issa, who served as chief of staff at the “combat and administrative support division” in the Palestinian terror group’s military wing, was killed in a strike in the Sabra neighborhood of Gaza City, according to the military.

The IDF said Issa was a “central source of knowledge and one of the last senior Hamas operatives who held high-level positions before October 7 and remained in the Gaza Strip.”

“In the past, Issa led Hamas’s force build-up efforts in the Gaza Strip, was one of the founders of the military wing’s operations division, served as head of the training division, and was a member of Hamas’s general military council,” the IDF said in a statement.

The military added that Issa “played a significant role in planning and executing the murderous massacre on October 7.”

During the war, including in recent days, “Issa served as head of combat support, advancing terror plans from the air and sea against Israeli civilians and IDF troops operating in the Gaza Strip,” the IDF said.

“Alongside advancing these plans, Issa worked to rebuild Hamas’s arrays that were damaged during the war,” the statement continued.

The October 7 attack saw thousands of Hamas-led terrorists invade Israel and kill some 1,200 people, mostly civilians targeted in their homes and at a music festival, and kidnap 251 people to Gaza as hostages, amid widely documented atrocities.

Fifty of the hostages still remain in the Strip. They include the bodies of at least 28 confirmed dead by the IDF. Twenty are believed to be alive and there are grave concerns for the well-being of two others, Israeli officials have said. Hamas is also holding the body of an IDF soldier killed in Gaza in 2014.

The Hamas-run Gaza health ministry says more than 53,000 people in the Strip have been killed or are presumed dead in the fighting so far, though the toll cannot be verified and does not differentiate between civilians and fighters. Israel says it has killed some 20,000 combatants in battle as of January and another 1,600 terrorists inside Israel during the October 7 onslaught.

Israel has said it seeks to minimize civilian fatalities and stresses that Hamas uses Gaza’s civilians as human shields, fighting from civilian areas including homes, hospitals, schools and mosques.