JERUSALEM (Reuters) - Hamas handed over the bodies of four Israeli hostages while it waited for hundreds of Palestinian prisoners to be released by Israel in return, the last such exchange agreed as part of a fragile truce in Gaza.

The ceasefire came into effect on January 19 and has largely held, despite numerous setbacks. But its first phase is due to end this week and the fate of its next phase, which aims to end the war, remains unclear. Hamas said that it has not received any proposals so far.

After days of impasse, Egyptian mediators secured the handover of the final four hostage bodies in the deal's first phase, for 620 Palestinians either detained by Israeli forces in Gaza or jailed in Israel.

Hamas handed over four bodies to the Red Cross, an Israeli security source told Reuters. Hamas had previously identified the bodies as those of Tsachi Idan, Itzhak Elgarat, Ohad Yahalomi and Shlomo Mantzur, all of whom were abducted during the October 7, 2023 attack from their kibbutz homes near Gaza, to the Red Cross.

The handover did not include a Hamas ceremony.

The staged ceremonies in which living hostages and coffins carrying hostage remains were displayed on stage before a crowd in Gaza drew strong criticism, including from the United Nations.

Israel had refused to release more than 600 Palestinian prisoners and detainees on Saturday after Hamas handed over six hostages in such a ceremony.

The Palestinian detainees due to be released include 445 men and 24 women and minors arrested in Gaza, as well as 151 prisoners serving life sentences for deadly attacks on Israelis, according to a Hamas source.

A bus carrying some of the released prisoners was seen leaving an Israeli jail in the West Bank. A hospital in Gaza will receive them, Hamas said.

The first phase of the ceasefire included the exchange of 33 Israeli hostages in total for around 2,000 Palestinian prisoners and detainees, and the withdrawal of Israeli troops from some positions in Gaza as well as an influx of aid.

But with the 42-day truce due to expire on Saturday, it remains unclear whether an extension that could see more of the 59 remaining hostages go free, will be agreed or whether negotiations can begin on a second stage of the deal.

(Reporting by Rami Amichay, Nafisa Eltahir, Yomna Ehab, Maayan Lubell, Ali Sawafta, Nidal al-Mughrabi; Additional reporting by Clauda Tanios and Jana Choukeir in Dubai, Emily Rose in Tel Aviv, Writing by James Mackenzie and Kylie Madry; editing by Mark Heinrich, William Maclean and Deepa Babington)