JERUSALEM >> Israel and Hamas on Sunday accused each other of violating the already fragile Gaza Strip ceasefire deal after Israel delayed the release of hundreds of Palestinian prisoners who were supposed to be exchanged for hostages.

The office of Israel’s prime minister, Benjamin Netanyahu, said the prisoners would not be freed until the release of further hostages “has been assured,” and Hamas committed to letting them go without “humiliating ceremonies.”

The growing tensions come after a week of mutual recriminations and strained nerves on both sides. The delay raised more questions about the future of the ceasefire for Gaza, with a temporary, six-week truce set to expire March 1.

There is no clarity yet about a possible extension, or even whether serious negotiations have begun. Some members of Israel’s right-wing government are pressing for a resumption of the fighting after the initial phase of the ceasefire, which has provided a brief lull in the devastating war set off by the Hamas-led attack on Israel on Oct. 7, 2023.

On Saturday, Hamas released six Israeli hostages, the last living captives set to be freed in the first phase of the ceasefire. Earlier it had handed over the remains of four hostages, including those of Shiri Bibas and her two young children, who were all taken alive during the 2023 assault.

Israel was supposed to release 620 Palestinian prisoners and detainees in return, the largest group of detainees to be let go since the ceasefire in Gaza began last month, but it delayed the move, citing what Netanyahu’s office described as Hamas’ “cynical exploitation” of the hostages for propaganda purposes.

Late Saturday, dozens of Palestinian families, their faces somber, left a venue in Ramallah in the Israeli-occupied West Bank where some prisoners were supposed to appear, after waiting there for hours in the hope of reuniting with their loved ones. Many families said they had received no official communication regarding the delayed release, relying instead on media reports and word of mouth.

Hamas has been releasing hostages in performative ceremonies aimed at showing that it is still in control of Gaza, a practice that many Israeli officials have condemned. On Saturday, five of the six living hostages were paraded on a stage, flanked by masked gunmen, prompting outrage in Israel. One hostage was seen on a stage kissing the heads of masked gunmen, as if in gratitude. His relatives later said he had been instructed to do so by a Hamas cameraman.

Anger was further inflamed when Hamas published propaganda video footage Saturday night showing two other Israeli hostages who had been forced to watch three of their fellow captives being released.

Repeatedly putting their shorn heads in their hands, the pair pleaded on camera for their freedom. Rights groups and international law experts say that a hostage video is, by definition, made under duress, and the statements in it are usually coerced. Israeli officials have called past Hamas videos a form of “psychological warfare,” and experts say their production can constitute a war crime.

In a statement Sunday, Netanyahu’s office accused Hamas of violating its agreement with Israel and said the prisoner releases would be postponed “until the release of the next hostages has been assured, and without the humiliating ceremonies.” On Thursday, Hamas is supposed to hand over the bodies of four more dead Israelis under the terms of the initial phase of the ceasefire.

Izzat Al-Rishq, a member of Hamas’ political bureau, said in a subsequent statement Sunday that Netanyahu’s decision to delay the prisoner releases “reflects a deliberate attempt to disrupt the agreement.” Al-Rishq also accused Israel of humiliating Palestinian prisoners and detainees during the release process, mistreating them “until the very last moments” and banning their families from holding celebrations.

Dozens of the prisoners slated to be released are serving life sentences for deadly attacks in Israel, while others had not been formally charged.

The recriminations came after an already turbulent week. On Thursday, Hamas returned four bodies it said were those of hostages who had died in captivity, among them that of Bibas. But forensic testing by Israel determined that the body was not hers. Late Friday, Hamas transferred another set of remains, which Israeli officials confirmed early Saturday as those of Bibas. The kidnapping and deaths of Bibas and her young children have become a symbol of Israeli grief and anguish.