Citing the latest data from the United Nations Satellite Centre (UNOSAT), Lazzarini highlighted the extensive destruction in Gaza, emphasizing that the damage goes beyond physical infrastructure.

“Every day this war goes on, the destruction of a whole community continues,” Lazzarini said in a post on X.

“Beyond the brick and stone, these are people’s homes, schools, markets and places of worship.”

The UNRWA chief expressed concern about the impact on Gaza’s social fabric, stating: “The once closely-tied society and kinship are being torn apart day after day, under our watch.”

Lazzarini stressed the urgent need for both a cease-fire and efforts to rebuild community ties. “With a ceasefire comes equally the urgency to rebuild the social fabric and community ties,” he added.

Israel has continued a devastating military offensive in the Gaza strip since an Oct. 7, 2023 Hamas attack despite a UN Security Council resolution demanding an immediate cease-fire.

Nearly 40,000 Palestinians have since been killed, mostly women and children, and over 91,700 injured, according to local health authorities.

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.

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 added Israel was aware of the presence of displaced people inside the school.

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 announced 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.

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”.

“The massacre at al-Tabin school in the Daraj neighbourhood in central Gaza City is a horrific crime that constitutes a dangerous escalation,” Hamas announced in a statement.

Izzat al-Rishq, a member of the Palestinian group’s political bureau, stressed there were no armed men at the school.

Israel’s claims of the school being used as the group’s command centre are “excuses to target civilians, schools, hospitals, and refugee tents, all of which are false pretexts and exposed lies to justify its crimes”.

“We call on our Arab and Islamic countries and the international community to fulfill their responsibilities and take urgent action to stop these massacres and halt the escalating Zionist aggression against our people and defenseless citizens,” the statement read.

Fatah, the rival Palestinian faction that last month signed a “national unity” agreement with Hamas, said in a statement the attack was a “heinous bloody massacre” that represents the “peak of terrorism and criminality”.

“Committing these massacres confirms beyond a shadow of a doubt its efforts to exterminate our people through the policy of cumulative killing and mass massacres that make living consciences tremble,” it added.

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.