The release of the first hostages held by Hamas militants in Gaza has been delayed until at least Friday, Israel's national security adviser said in a statement late Wednesday.
"The release will begin according to the original agreement between the parties, and not before Friday," Tzachi Hanegbi said, adding that talks on the deal were continuing.
Hanegbi gave no reason for the delay, and it was not clear when Israel would begin a four-day pause in its attacks on Gaza, which was part of the agreement previously announced by the warring parties. The truce had been set to take effect at 10 a.m. local time Thursday.
Qatar, which helped broker the deal along with the United States and Egypt, had earlier said Hamas, in stages, would release 50 women and children in the coming days, while Israel was expected to free 150 Palestinian prisoners.
None of the identities of those being freed has been disclosed, but U.S. officials said they thought some of the nine American hostages believed to be held by Hamas would be among those released.
Fighting continued Wednesday, with explosions seen over Gaza and Hamas firing missiles into Israel.
One airstrike hit a residential building in the southern Gaza town of Khan Younis, reportedly killing 17 people, including children, while in northern Gaza, about 60 bodies and 200 people wounded by heavy fighting were brought into the Kamal Adwan Hospital overnight.
The hospital's director, Dr. Ahmed al-Kahlout, told Al Jazeera television on Wednesday that the medical center was using cooking oil to keep its generator running. The Al-Aqsa Martyrs Hospital in central Gaza said 128 bodies were brought in overnight after nearby strikes, more than double the number that arrived Tuesday night.
The deal encompassing the hostage-prisoner release and temporary truce evolved after weeks of stop-and-start negotiations amid the continuing bloodshed in Gaza.
Israel began its military campaign to wipe out Hamas after the U.S.-designated terrorist group launched a cross-border attack on October 7. Israel said 1,200 people were killed that day and about 240 hostages taken back to Gaza.
The Hamas-run Gaza health ministry says more than 12,000 Palestinians, including at least 5,000 children, have been killed in Israel's military offensive in the Gaza Strip.
U.S. President Joe Biden expressed his appreciation to Sheikh Tamim bin Hamad Al-Thani of Qatar and President Abdel-Fattah el-Sissi of Egypt for helping broker the deal. Biden praised "the commitment" of Israeli Prime Minister Benjamin Netanyahu for the brief stop in the fighting "to ensure this deal can be fully carried out and to ensure the provision of additional humanitarian assistance to alleviate the suffering of innocent Palestinian families in Gaza."
But Netanyahu said Israel would resume the war after the truce and keep fighting "until we achieve all our goals," including the destruction of Hamas' fighting and governing abilities and the return of all hostages.
Several countries, including Britain, France, China and Russia, also welcomed the agreement.
Qatar's Tamim said he hoped the deal would eventually lead to a permanent cease-fire and "serious talks" on resolving the Israeli-Palestinian conflict.
Israel said the four-day stop in fighting would be extended an extra day for every additional 10 hostages freed by Hamas. The International Committee of the Red Cross said it could assist with any release.
Israel's Justice Ministry published a list of 300 prisoners eligible to be let out as part of the deal, mainly teenagers detained over the past year for rock-throwing and other minor offenses. Under Israeli law, the public has 24 hours to object to any release.
The Israeli military says it has detained more than 1,850 Palestinians in the West Bank since the war began, mostly suspected Hamas members. More than 200 Palestinians have been killed there, mainly during battles triggered by army raids. Attacks by Jewish settlers have also surged.
The pause in fighting will also allow for more humanitarian aid to reach Palestinians in Gaza. Such assistance has been sharply curtailed since the fighting began.
The U.N. Office for the Coordination of Humanitarian Affairs said 79 trucks reached the Palestinian enclave on Tuesday, bringing the total during the past month to 1,399 truckloads of aid. The agency said an average of 10,000 truckloads of commercial and humanitarian commodities were reaching Gaza each month prior to the conflict.
The United Nations said more than 1.7 million people have been displaced within Gaza, including 930,000 people staying at over-capacity U.N.-run shelters.
European Union foreign policy chief Josep Borrell welcomed the Israel-Hamas agreement and called for the release of all hostages held by Hamas.
"The humanitarian pause must be used to provide as much urgently needed aid as possible to the civilians enduring the devastating war in Gaza," Borrell said in a statement.
U.N. Secretary-General Antonio Guterres called the deal a "step in the right direction."
"The United Nations will mobilize all its capacities to support the implementation of the agreement and maximize its positive impact on the humanitarian situation in Gaza," said a statement by Farhan Haq, deputy spokesperson for the secretary-general.
French Foreign Minister Catherine Colonna also welcomed the deal, telling France Inter Radio that France hoped French nationals would be among those released.
In Russia, Kremlin spokesperson Dmitry Peskov called the deal the "first good news" in a long time regarding the conflict.
British Foreign Secretary David Cameron hailed the agreement as "a crucial step towards providing relief to the families of the hostages and addressing the humanitarian crisis in Gaza."
