Tel Aviv, Israel - Israel on Thursday abruptly accused Hamas of backtracking on parts of a fragile Gaza ceasefire and hostage release deal, and killed dozens of Palestinians in airstrikes ahead of an expected vote by the cabinet.

The truce, announced by mediator Qatar and Israel's sponsor, the US, on Wednesday, would take effect on Sunday and involve the exchange of Israeli hostages for Palestinian prisoners, after which the terms of a permanent end to Israel's destruction of Gaza would be finalized.

But the office of Prime Minister Benjamin Netanyahu said Thursday that Hamas had "reneged on parts of the agreement reached... in an effort to extort last-minute concessions," offering no details or evidence for his allegations.

It also said that the Israeli cabinet, which has yet to approve the agreement, "will not convene until the mediators notify Israel that Hamas has accepted all elements of the agreement"

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Hamas political bureau member Sami Abu Zuhri said there was "no basis" to Israel's accusations, and reiterated that the organization has accepted the deal as presented by mediators.

As Palestinians came out to celebrate news of an imminent ceasefire, Israel launched airstrikes all over the territory, killing at least 73 people and wounding hundreds.

Saeed Alloush, who lives in north Gaza, said he and his loved ones were "waiting for the truce and were happy," until overnight strikes killed his relatives.

"It was the happiest night since October 7" until "we received the news of the martyrdom of 40 people from the Alloush family," he said.

The agreement followed months of fruitless negotiations as Israel and the US scuppered effort after effort. If finalized, it would pause hostilities one day before the inauguration of US President-elect Donald Trump.

Netanyahu spoke with both Joe Biden and Trump on Wednesday, the Israeli leader's office said, thanking them for their help securing the agreement but also cautioning that "final details" were still being worked on.

But two party leaders in the prime minister's cabinet have publicly opposed the agreement.

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Finance Minister Bezalel Smotrich said it was a "dangerous deal," while National Security Minister Itamar Ben Gvir – a self-described fascist – called it "disastrous".

Israeli media said the government's ratification of the agreement may be delayed in part due to disagreements within the ruling coalition.

Citing a source close to talks, Kan public broadcaster said Netanyahu wanted to protect the integrity of his government but that Smotrich was presenting a "real threat."

During an initial 42-day ceasefire, 33 hostages would be released, Qatari Prime Minister Sheikh Mohammed bin Abdulrahman al-Thani, including women, "children, elderly people, as well as civilian ill people and wounded."

Also in the first phase, Israeli forces would withdraw from Gaza's densely populated areas and allow displaced Palestinians to return "to their residences," he said.