GENEVA (AP) — The U.N. human rights office is citing possible war crimes by Israeli forces and Palestinian armed groups in connection with a deadly raid by Israeli forces that freed four hostages over the weekend and killed hundreds of Palestinians.

Office spokesman Jeremy Laurence expressed concerns about possible violations of rules of proportionality, distinction and precaution by the Israeli forces in Saturday's raid at the urban Nuseirat refugee camp.

Palestinian health officials say at least 274 Palestinians, including dozens of women and children, were killed in the operation.

Laurence said Palestinian armed groups who are holding hostages in densely populated areas are putting the lives of nearby civilians and the hostages at "added risks" from the hostilities.

"All these actions by both parties may amount to war crimes," he told a regular U.N. briefing in Geneva.

"It was catastrophic, the way that this was carried out in that civilians — again — were caught smack bang in the middle of this," Laurence added.

Alluding to the "ordeal" faced by hostages and their families, he said: "The fact that four hostages are now free is clearly very good news. These hostages should never have been taken in the first place. That's a breach of international humanitarian law. They must be freed. All of them. Promptly."

Israel launched its war against Hamas after the group's Oct. 7 attack, in which militants stormed into southern Israel, killed some 1,200 people — mostly civilians — and abducted about 250.

Israel's war against Hamas in Gaza has killed more than 36,730 people, according to Gaza's Health Ministry, which does not distinguish between combatants and civilians in its count. Palestinians are facing widespread hunger because the war has largely cut off the flow of food, medicine and other supplies. U.N. agencies say over 1 million in Gaza could experience the highest level of starvation by mid-July.