Mediators have reached a deal to release Palestinian prisoners who were originally set to be freed by Israeli authorities last Saturday, along with the handover of Israeli hostages' bodies by Hamas, an Egyptian official said on Wednesday.

The source, who was briefed on the matter, said the handovers would take place under Egyptian supervision but did not specify the release date.

Al-Nasser Salah al-Deen Brigades, a Gaza-based militant group allied to Hamas, said it will release the body of Israeli hostage Ohad Yahalomi on Thursday.

Ohad's is one of four bodies set to be released by Hamas in the first phase of the Gaza ceasefire deal.

The release of 620 Palestinian prisoners was meant to occur just after six Israeli hostages were released last Saturday.

Israel says the release would be delayed "until the release of the next hostages is assured, and without the humiliating ceremonies" at handovers of Israeli captives in Gaza.

The Oct. 7 attack in southern Israel killed about 1,200 people, mostly civilians, according to Israeli tallies. Israel's subsequent military offensive has killed more than 48,000 Palestinians, mostly women and children, according to Gaza's Health Ministry.

The three-stage ceasefire which came into effect on Jan. 19 is now nearing the end of its first phase. 

It has largely held despite accusations of violations by both sides