(Reuters) - The release of hostages under a temporary truce between Israel and Palestinian Hamas militants will not happen before Friday, Israel's national security adviser said, thwarting hopes of relatives that some would be freed on Thursday.
Israel and Hamas agreed early on Wednesday to a ceasefire in Gaza for at least four days, to let in humanitarian aid and free at least 50 hostages held by militants in the enclave in exchange for at least 150 Palestinians jailed in Israel.
The starting time of the truce and release of hostages captured by Hamas during its Oct. 7 attack on Israel has yet to be officially announced. An Egyptian security source said mediators had sought a start time of 10 a.m. on Thursday.
"The negotiations on the release of our hostages are advancing and continuing constantly," Israeli National Security Adviser Tzachi Hanegbi said in a statement released by the prime minister's office.
"The start of the release will take place according to the original agreement between the sides, and not before Friday," it said.
Israel's public broadcaster Kan, citing an unidentified Israeli official, reported there was a 24-hour delay because the agreement was not signed by Hamas and mediator Qatar. The official said they were optimistic the agreement would be carried out when it was signed.
"No one said there would be a release tomorrow except the media ... We had to make it clear that no release is planned before Friday, because of the uncertainty that hostages' families are facing," Kan quoted a source in Israeli Prime Minister Benjamin Netanyahu's office as saying.
Israeli media, citing anonymous officials, reported the pause in fighting with Hamas also would not start before Friday. Israel's Ynet news website reported that Israel had not yet received the names of the hostages slated for release by Hamas.
Since the Hamas attack on southern Israel that surprised the government and shocked Israelis, five hostages have been recovered alive. Israel says 1,200 people were killed, mostly civilians and about 240 hostages of different nationalities taken hostage by Islamist gunmen.
In retaliation, Israel has subjected Hamas-ruled Gaza to a siege and relentless bombardment. More than 14,000 Gazans have been killed, around 40% of them children, according to medical officials in the territory.
Palestinian media reported that Israeli aircraft and artillery struck Gaza's southern city of Khan Younis in at least two waves early on Thursday.
In Israel, sirens warning of incoming rocket fire from Gaza blared in communities near the border with the enclave early on Thursday, the military said. There were no reports of damage or injuries.