The civilian, Arbel Yehud, should have been among the first two groups of hostages released on Jan. 19 and Jan. 25 under the cease-fire deal, according to the Israeli authorities.

Tens of thousands of Palestinians began returning to a ravaged northern Gaza and what was left of their homes and families, after Hamas agreed to release more hostages than expected this week to keep its cease-fire with Israel in place.

Tens of thousands of Palestinians streamed along the main roads leading north in Gaza on Monday, jubilant to be returning home after months of living in temporary shelter but fearing what might remain of their homes amid the bombed-out ruins.