War raged on in Gaza on Thursday, as a proposed truce and release of hostages was delayed for at least another day.

Columns of black smoke could be seen rising above northern Gaza’s war zone from across the fence in Israel as daylight broke over the strip. Israel said the release of hostages, meant to be accompanied by the war’s first ceasefire, would be delayed at least until Friday.

The Israeli military said it had launched 300 air strikes in the past day, and sounded sirens warning of cross-border rocket launches by Palestinian armed groups. Palestinian media reported Israeli strikes in the northern areas as well as in the southern city of Khan Younis, where Israel has told residents of the north to seek shelter.

“The negotiations on the release of our hostages are advancing and continuing constantly,” Israeli National Security Adviser Tzachi Hanegbi said in a statement overnight. “The start of the release will take place according to the original agreement between the sides, and not before Friday.”

The first truce in the seven-week-old war is meant to be accompanied by the release of 50 women and children hostages captured by militants who raided Israel on Oct. 7, in exchange for 150 Palestinian detainees from Israeli jails.

The agreement was announced on Wednesday morning, but more than a day later an expected announcement of the official start time had yet to materialise. Mediator Qatar said on Thursday it could make an announcement within hours.

Israel has said the truce could last beyond the initial four days as long as the militants free at least 10 hostages per day. A Palestinian source has said a second wave of releases could allow as many as 100 hostages to go free by month’s end.

Both sides have said they will go back to fighting once the truce is over.

“We are not ending the war. We will continue until we are victorious,” the chief of the Israeli general staff, Lieutenant-General Herzi Halevi, told commanders in a video released by the military on Thursday.

Israel launched its war in Gaza after gunmen from Hamas burst across the border fence, killing 1,200 people and seizing about 240 hostages, according to Israeli tallies. Since then, more than 14,000 Gazans have been killed by Israeli bombardment, around 40% of them children, according to health authorities in the Hamas-ruled territory.

‘We need to know if they are alive’

The delay to the start of the truce meant another day of worry for Israeli relatives of the hostages who say they still know nothing about the fate of missing loved ones, and of fear for Palestinian families trapped inside the Gaza combat zone.

“We need to know they are alive, if they’re okay. It’s the minimum,” said Gilad Korngold, desperate for any information about the fate of seven of his family members, including his 3-year-old granddaughter, believed to be among the hostages.

Palestinian media reported at least 15 people killed in air strikes on Khan Younis, Gaza’s main southern city, where hundreds of thousands of Gazans are sheltering from the Israeli advance in the north. Reuters could not immediately verify the toll there.

Israeli officials did not give a full explanation for the delay in the start of the truce but said full arrangements still needed to be made for the release of the hostages to begin.

“This would appear to be a matter of finalising the details,” Energy Minister Israel Katz, a member of the security cabinet, told Army Radio in an interview. “Israel did not announce in advance that this would happen today. The understanding was that it would happen as Friday approaches.”

White House spokesperson Adrienne Watson said final logistical details for the release were being worked out. “That is on track and we are hopeful that implementation will begin on Friday morning,” Watson said.

Israel’s public broadcaster Kan, citing an unidentified Israeli official, reported there was a 24-hour delay in the truce because the agreement was not signed by Hamas and Qatar.

“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.

Israel’s Ynet news website reported that Israel had not yet received the names of the hostages slated for release by Hamas.