Israel said on Sunday that it was delaying the release of 620 Palestinian prisoners, originally planned for the day before, until Hamas had met its terms, underlining the fragile nature of the Gaza truce.

Prime Minister Benjamin Netanyahu’s office said the prisoners would not be released until Israel was given assurances on the release of other hostages and that the handovers would be done “without the humiliating ceremonies.” This was in reaction to Hamas parading hostages in front of crowds, a move condemned by the UN for being against international norms.

The postponement came after Hamas released six live Israeli captives on Saturday as the last set of surviving prisoners to be set free during the initial stage of the ceasefire. The militant faction will deliver next week the corpses of four Israeli hostages killed by Hamas during a raid into Egypt, though whether Israel demands other guarantees of such a development has not yet been determined.

Hostilities between the two have been elevated, with each accusing the other of ceasefire breaches since the beginning of the truce on January 19. Hamas official Abdul Latif Al-Qanou criticized Israel for not releasing Palestinian inmates on time. In spite of this, the ceasefire holds.

Among those released on Saturday were Eliya Cohen, Omer Shem Tov, and Omer Wenkert, all captured in Hamas’ Oct. 7 attack. They were surrendered in central Gaza, accompanied by armed men and forced to wave on a stage. Other captives were Tal Shoham and Avera Mengistu, and Hisham Al-Sayed was released without a ceremony.

With 63 hostages remaining in Gaza, the efforts of mediation by Egypt and Qatar persist, as negotiations regarding the next phase of the ceasefire agreement proceed. Yet, the road to a sustainable solution remains unclear.