Two-thirds of its schools in Gaza have been hit and bombed since the start of the war in Gaza, with many being severely damaged and hundreds of people killed, according to the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA).

"Four schools hit in the last four days. Since the war began, two-thirds of UNRWA schools in Gaza have been hit, some were bombed out, many severely damaged," said Philippe Lazzarini, commissioner-general of UNRWA, in a post on X, formerly known as Twitter, on Wednesday.

"The blatant disregard of international humanitarian law cannot become the new normal," UNRWA said in an official statement on its website.

Amid reports of intensified heavy shelling in north, central and southern Gaza, Lazzarini confirmed on Wednesday that schools-turned-shelters have been "bombed-out" as a result of the latest escalation. As a result, 520 people were killed and nearly 1,600 were injured while seeking some safety, said UNRWA.

"Gaza is no place for children," Lazzarini posted. "Schools have gone from safe places of education and hope for children to overcrowded shelters and often ending up a place of death and misery. Nine months in, under our watch, the relentless, endless killings, destruction and despair continue."

On Tuesday, at least 25 people were killed after an Israeli strike near a school building sheltering displaced Gazans in eastern Khan Younis, southern Gaza, according to local health authorities.

Exclusive footage from the school, obtained by Al Jazeera, shows young Palestinians playing soccer outside the school as dozens of people watch. Then a loud explosion is heard, sending people running for cover.

A Palestinian boy told Al Jazeera he lost several relatives in the attack. "We were sitting and a missile fell and destroyed everything," he said, sobbing. "I lost my uncle, my cousins and my relatives."

Meanwhile, France said it was deeply concerned over the recent Israeli strikes on schools in Gaza, according to an official statement on Wednesday.

"We call on clarifying all the facts on these strikes," the statement of France read. "It is unacceptable that schools that are hosting civilian populations displaced due to the conflict are targeted."

Apart from France, Germany said Wednesday that a deadly Israeli strike on a school in southern Gaza being used as a shelter was "unacceptable" and called for a rapid investigation into the incident.

"People seeking shelter in schools getting killed is unacceptable. Civilians, especially children, must not get caught in the crossfire," the Foreign Ministry of Germany posted on X. "The repeated attacks on schools by the Israeli army must stop and an investigation must come quickly."

Stepped-up Israeli military activity comes as the United States, Egyptian and Qatari mediators met with Israeli officials in Qatar's capital, Doha, for talks seeking a long-elusive ceasefire deal and an exchange of captives held by Hamas for Palestinians held in Israeli prisons.

There is no sign of stopping the attacks from Israel even as the Doha truce talks continue. The Israeli military issued a sweeping directive for all Palestinians to leave Gaza City on Wednesday, calling the area a "dangerous combat zone", according to Al Jazeera.

"Israel's instruction for people to leave Gaza city will only fuel mass suffering for Palestinian families," the UN humanitarian affairs office said in a statement Wednesday.

Ismail Haniyeh, the leader of Hamas, said on Monday that Israel's escalating assault has threatened talks at a crucial time and could bring negotiations "back to square one", according to Al Jazeera.

While Hamas still wants international mediators to guarantee that truce talks in Doha conclude with a permanent ceasefire, Israeli Prime Minister Benjamin Netanyahu has insisted he will not agree to any deal forcing Israel to stop its campaign in Gaza without eliminating Hamas.

mikegu@chinadailyhk.com