Israel is supporting armed groups of Palestinians in Gaza in what it says is a move to counter Hamas. But officials from the U.N. and aid organizations

The war began when Hamas-led fighters attacked southern Israel on Oct. 7, 2023, killing some 1,200 people, mostly civilians, and taking 251 hostage. They are still holding 53 captives, less than half of them believed to be alive, after most of the rest were released in ceasefire agreements or other deals.