Hamas said it’s ready to release a second group of hostages to Israel, resolving a dispute that threatened an early end to a four-day truce in Gaza and forced another round of international diplomacy.

The militant group delayed the release of 13 Israeli hostages earlier Saturday, accusing Israel of violating the terms of the truce especially regarding the delivery of humanitarian aid to northern Gaza, which has been hit hardest in the war that began last month. Israeli officials denied violating the agreement.

“There is an agreement that we started to carry out,” Israeli army spokesman Rear Admiral Daniel Hagari said in a briefing. “We want to ensure that the agreement is implemented and if it isn’t we will continue to fight.”

Hours after the proposed time for the release had elapsed, Hamas official Bassem Naim told Bloomberg News that mediators “conveyed the occupation’s commitment to all the conditions stipulated in the agreement.”

Qatar’s state-run QNA news service said Israel would free 39 Palestinian prisoners in exchange for the release of 13 Israelis. Another seven foreigners held by Hamas would also be freed, according to the report.

The last-minute snag underscored the fragility of the truce and deep distrust between Hamas and Israel. Hamas militants infiltrated Israel on Oct. 7, killing 1,200 people and abducting about 240 hostages. Their recovery has become an urgent priority for Prime Minister Benjamin Netanyahu’s shaky government.

Israel has unleashed its military might on the small, crowded Gaza Strip after the attack. At least 15,000 people have been killed, according to the health ministry run by Hamas, which the US and the European Union have designated a terrorist group.

US President Joe Biden earlier Saturday spoke with Qatari leaders “on potential holdups to the deal and mechanisms to resolve them,” said Adrienne Watson, a spokeswoman for the National Security Council. Qatar has been the main negotiator in efforts to release the hostages.

Hamas said in a statement that six women and 33 minors will be released by Israel in the second group of Palestinian prisoners to be set free.

After weeks of negotiations, the two sides this week agreed to a limited truce, contingent on Hamas releasing a total of 50 hostages and Israel freeing 150 women and minors held in the nation’s prisons.

The first exchange on Friday went as planned: Hamas released 13 Israelis, some with dual citizenship and all women and minors. In a separate deal, it also released 10 Thai nationals and a citizen of the Philippines.

Israel then freed a first group of 39 jailed Palestinians.

Biden, who said the first day had “gone well,” was kept informed of developments Saturday and, after his call with the Qatari leaders, senior US officials were in “regular contact with the Israelis, Qataris, and Egyptians to overcome hurdles,” Watson said.

Author: Gwen Ackerman, Fares Akram and Akayla Gardner