More than 100 Palestinians have been killed and dozens wounded in an Israeli strike on a school sheltering displaced people in Gaza City, according to Palestinian officials.

Three Israeli bombs hit the al-Tabin school, located in Daraj district, Gaza’s civil defence agency said of the attack on Saturday which it described as a “horrific massacre”.

Women, children and the elderly are reported to be among the dead and the toll was expected to rise. The attack took place while people were performing morning prayers and triggered a fire that ripped through the building.

Reporting from Khan Younis in southern Gaza, Al Jazeera’s Hani Mahmoud said it was a “deliberate” attack on civilians but also “a violation of people’s religious rites as they were in a time considered sacred”.

Ismail al-Thawabta, the head of Gaza’s Government Media Office, told Al Jazeera that the Israeli army used three bombs weighing 2,000 pounds (907kg) each in its attack.

He said Israel was aware of the presence of displaced people inside the school.

The Israeli military said its air forces struck a “command and control centre” that “served as a hideout for Hamas terrorists and commanders” and was also a shelter for the residents of Gaza City.

Israeli forces have repeatedly attacked schools used as shelters, claiming they are command centres for Hamas, the Palestinian group that governs Gaza, to hide fighters and manufacture weapons.

Saturday’s attack was the fourth such incident in a week. Israel has not presented evidence to prove its claims that schools are being used by Hamas.

Hamas has denied Israeli accusations that it operates from civilian facilities such as schools and hospitals.

“The occupation army directly bombed the displaced people while they were performing the dawn prayer, and this caused the number of martyrs to rise rapidly,” the Gaza Government Media Office said in a statement following the attack.

Palestinian journalist Hossam Shabat reported that rescue teams were unable to help those trapped by the flames as the Israeli military cut water access to the area.

Many of the wounded rushed to the al-Ahli Hospital in Gaza City were in a critical condition, said Al Jazeera’s Mahmoud, severely bleeding from shrapnel or severely burned from the fire that broke out from the bombardment.

“Many are arriving either soaked in blood or already pronounced dead,” Mahmoud said, adding that the medical facility was on the brink of collapse and unable to provide adequate medical care.

Some of the bodies were hard to recognise, “so relatives at the hospital searching for their loved ones are struggling to find any way to identify them”, he added.

Reporting from Amman, Jordan, Al Jazeera’s Hamdah Salhut said, “The images coming out of the school immediately after the strike shows tens if not hundreds of bodies just on the ground, some of them in pieces.”

She also pointed out that looking at the images coming out of the school, “the number of injuries, the damage to the buildings, really disprove the claims that there was precise weaponry that was used there”.

The attack comes as Qatar, Egypt and the United States have called on Israel and Hamas to resume talks on August 15 to reach a ceasefire.

Gaza’s Ministry of Health says at least 39,699 people have been killed and 91,722 wounded in Israel’s war on the enclave. An estimated 1,139 people were killed in Israel during the Hamas-led attacks on October 7 and more than 200 were taken captive.