An Israeli airstrike hit a school-turned-shelter in Gaza City early Saturday, killing at least 80 people, Palestinian health authorities said, in one of the deadliest strikes in the 10-month-old war between Israel and Hamas.

The Israeli military acknowledged the strike, claiming it hit a Hamas command centre within the school. Hamas denied that.

The strike on the Tabeen school in central Gaza City also wounded 47 people, the Health Ministry said. The facility, like almost all of Gaza’s schools, has been used as a shelter for people who have been forced to flee their homes by the war.

Video from the scene showed walls blown out on the ground level of a large building. Concrete chunks and twisted metal lay atop the blood-soaked floor, along with clothing, toppled furniture and other debris. A blackened car with the windows blown out was covered in rubble.

Fadel Naeem, director of the al-Ahli hospital in Gaza City, told The Associated Press that the facility received 70 bodies of those killed in the strike and the body parts of at least 10 others.

The strike hit without warning in the early morning before sunrise as people were praying at a mosque inside the school, according to Abu Anas, a witness who worked to rescue people.

“There were people praying, there were people washing and there were people upstairs sleeping, including children, women and old people,” he said. “The missile fell on them without warning. The first missile, and the second. We recovered them as body parts.”

Three missiles ripped through the school and the mosque inside, where about 6,000 displaced people were taking shelter from the war, said Mahmoud Bassal, a spokesperson for the Civil Defense first responders who operate under the Hamas-run local government.

Many of the dead were unrecognisable, he said, adding that he expected the death toll to rise. Many of the casualties were women and children, he said.

According to the United Nations, 477 out of 564 schools in Gaza had been directly hit or damaged in the war as of July 6. In June, an Israeli strike on a school sheltering displaced Palestinians in central Gaza killed at least 33 people, including 12 women and children, according to local health officials.

On Thursday Israel’s military hit two schools sheltering displaced people in eastern Gaza City, killing at least 15 people, according to hospital officials.

Israel has blamed civilian deaths in Gaza on Hamas, saying the group endangers noncombatants by using schools and residential neighbourhoods as bases for operations and attacks.

Israeli intelligence indicated about 20 militants from Hamas and Islamic Jihad, including senior commanders, were using the Tabeen school compound to plan attacks on Israeli forces, Lt. Col. Nadav Shoshani, an Israeli military spokesman said in a statement on the social media platform X.

Izzat al-Rishq, a top Hamas official denied there were militants in the school.

Shoshani also questioned the casualty numbers issued by the Palestinian Health Ministry.

Israel said the targeted school was located next to a mosque serving as a shelter for Gaza City residents.

A cameraman working for The Associated Press said, however, that the mosque and the classrooms were in one building, with the prayer hall on the ground floor and the school above it. A missile appeared to have penetrated through the floor of the classrooms to the mosque below and then exploded, according to the cameraman.

The strike came as American, Qatari and Egyptian mediators renewed their push for the two parties to achieve a cease-fire agreement that could help calm soaring tensions in the region following the assassination of top Hamas political leader Ismail Haniyeh in Tehran and a senior Hezbollah commander in Beirut.

Egypt, which borders Gaza and serves as a key mediator, said the strike on the school showed Israel had no intention of reaching a cease-fire deal and ending the war.

Neighboring Jordan also condemned the attack, calling it a “blatant violation” of international law.

Israel’s campaign in Gaza has killed more than 39,600 Palestinians and wounded more than 91,700 others, according to the enclave’s Health Ministry. The war was triggered by Hamas’ Oct 7 attack, in which militants from Gaza stormed into southern Israel, killing around 1,200 people and abducting 250 others.