An Israeli air strike on a Gaza school compound housing displaced families killed about 100 people, the Hamas-run Gaza government says, as the Israeli military says it targeted Hamas militants there and cast doubt on the death toll.
Video from the site showed body parts scattered on the ground and more bodies being carried away and covered in blankets on the floor.
Empty food tins lay in a puddle of blood, with burnt mattresses and a child's doll among the debris.
The Hamas-run media office said in a statement that the strikes hit when people sheltering at the school were performing dawn prayers, leading to many casualties.
"So far, there are more than 93 martyrs, including 11 children and six women," Palestinian Civil Defence spokesman Mahmoud Bassal said in a televised news conference.
"There are unidentified remains."
About 6000 people had been sheltering at the compound, he said.
The Gaza health ministry has so far not provided casualty details.
In a statement in Hebrew, the Israeli military said the death toll was inflated.
It said about 20 Hamas and Islamic Jihad militants were operating at the site.
"The compound, and the mosque that was struck within it, served as an active Hamas and Islamic Jihad military facility," Lieutenant Colonel Nadav Shoshani said on X.
"According to an initial review, the numbers published by the Hamas-run Government Information Office in Gaza, do not align with the information held by the IDF (Israel Defence Forces), the precise munitions used, and the accuracy of the strike," Shoshani said.
A military official said the part of the mosque struck was a men's area where no women or children were present.
"This was verified by intelligence and the strike was carried out using three small, precise munitions which cannot cause the scale of damage that the Palestinians are reporting," the official said.
At the news conference in Gaza City, Bassal said the strike hit "the upper and ground floors of the school".
"The upper floor included women and children and the ground floor included people who were praying," he said.
"They were directly hit."
Hamas said the strike was a horrific crime and a serious escalation.
Izzat El-Reshiq, a member of Hamas' political office, said in a statement the dead did not include a "single combatant".
Tens of thousands of displaced Palestinians have sought shelter in Gaza's schools, most of which have stopped functioning since the start of the war 10 months ago.
A spokesperson for Palestinian President Mahmoud Abbas, Nabil Abu Rudeineh, urged Israel's ally Washington to put an end to the "blind support that leads to the killing of thousands of innocent civilians, including children, women, and the elderly".
Egypt, Qatar and Saudi Arabia condemned the strike, which came as mediators pushed to resume ceasefire talks.
Egypt said that the killing of Gaza civilians showed Israel had no intention to end the war.
Qatar's foreign ministry described the strike as a "horrific massacre".
Egypt, the US and Qatar have scheduled a new round of ceasefire negotiations for Thursday, as fears grow of a broader conflict involving Iran and its Lebanese ally Hezbollah.
Israeli Prime Minister Benjamin Netanyahu said a delegation would be sent to the August 15 talks.
Israel launched its assault on Gaza after Hamas fighters stormed into southern Israel on October 7, killing 1200 people, mostly civilians, and capturing more than 250 hostages, according to Israeli tallies.
Almost 40,000 Palestinians have been killed in the Israeli offensive in Gaza, according to the Palestinian health ministry, which does not distinguish between combatants and civilians.
Israel has lost 329 soldiers in Gaza.
