Israeli airstrikes pounded Gaza and killed more than 400 people, Palestinian health authorities said on Tuesday, in an onslaught that ended weeks of relative calm after talks to secure a permanent ceasefire stalled.

Israel and Palestinian militant group Hamas each accused the other of breaching the truce, which had broadly held since January, offering respite from war for the 2.3 million inhabitants of Gaza, where most buildings have been reduced to rubble.

Hamas, which still holds 59 of the 250 or so hostages Israel says the group seized in its October 7, 2023 attack, accused Israel of jeopardizing efforts by mediators to negotiate a permanent deal to end the fighting, but the group made no threat of retaliation.

Israeli Prime Minister Benjamin Netanyahu’s office said he would deliver a statement at 8 pm. (1800 GMT), while Israeli media reported the cabinet would meet at 9pm.

Netanyahu said earlier he ordered strikes because Hamas had rejected proposals to secure a ceasefire extension, and pledged to step up military action.

The strikes hit houses and tent encampments from the north to the south of the Gaza Strip, and Israeli tanks shelled from across the borderline, witnesses said. Gaza’s Hamas-run health ministry said 404 people had been killed in one of the biggest single-day tolls since the war erupted.

“It was a night of hell. It felt like the first days of the war,” said Rabiha Jamal, 65, a mother-of-five from Gaza City.