China's envoy to the United Nations on Tuesday "strongly condemned" Israel's attack on a school sheltering displaced people in Gaza City.

Three Israeli rockets struck the Al-Taba'een School on Saturday, where many displaced Palestinians were seeking shelter and participating in dawn prayers. More than 100 Palestinians were killed, and dozens were injured in the assault, the Hamas-run Gaza government media office said.

Israel said it targeted the school because Hamas fighters were sheltering there.

"China strongly condemns the assault," Fu Cong, China's permanent representative to the UN, told a Security Council meeting on Tuesday to discuss the attack.

"Civilians and civilian infrastructure should never be targets of military action — this is a red line defined by international humanitarian law. The repeated attacks on schools, where large numbers of civilians seek refuge, are appalling," said Fu.

He said that over the past 10 months, millions of people in Gaza have had their homes destroyed, and families have been torn apart, forcing them to move from place to place in search of safety, only to face bombings and the constant threat of death.

"There is no longer any safe haven in Gaza," Fu said.

Three schools in Gaza City were hit within 48 hours between Aug 3 and 4 and two schools hit on Aug 8, with Al-Taba'een on Saturday the latest such attack, according to Lisa Doughten, director of the Financing and Partnerships Division at the UN Office for the Coordination of Humanitarian Affairs.

At least 21 schools in Gaza, all serving as shelters, have been attacked, resulting in at least 274 fatalities, according to the UN Human Rights Office. Saturday's strike was one of the deadliest on a school sheltering displaced people since the conflict began, said Doughten.

Fu urged the US to push Israel to halt its military operations in Gaza as Israel's "largest arms supplier".

"An immediate and lasting cease-fire is the urgent hope of the people of Gaza and a strong consensus within the international community," he said, noting that the council two months ago passed its first cease-fire resolution, and the US said that Israel had accepted a cease-fire agreement.

"But the reality is quite the opposite. We have seen no credible signs of Israel committing to a cease-fire; instead, there is an escalation in military actions and rising civilian casualties," Fu said.

"We urge the US to act with sincerity and responsibility, pushing Israel to halt its military operations in Gaza and end the killing of civilians as soon as possible," he said.

Israeli Finance Minister Bezalel Smotrich last week said it might be "justified and moral" to starve 2 million people in Gaza in order to free Israeli hostages.

Fu condemned the statement, calling it "horrifying" and "entirely unacceptable". "Hunger should never be used as a weapon; humanitarian issues should not be politicized; and civilian lives should not be bargaining chips," he said.

He then urged Israel to fulfill "its international humanitarian obligations, open all border crossings, and ensure the rapid, large-scale, and safe delivery of humanitarian aid".

Separately, last week, Israeli surveillance footage reportedly showed Israeli soldiers sexually assaulting a Palestinian detainee inside the Sde Teiman prison.

Fu said China is "seriously concerned" about the incident and called for an investigation and accountability.

"China urges Israel to immediately halt all settlement activities, effectively curb the escalating settler violence, and stop undermining the foundation of the two-state solution," Fu continued.

He reiterated that the two-state solution "is the only viable path to resolving the Israeli-Palestinian conflict. China supports the establishment of an independent Palestinian state and advocates for convening a larger, more authoritative and more effective international conference," he said.

UN Secretary-General António Guterres on Monday also condemned the school attacks in Gaza.

"The Secretary-General condemns the continued loss of life in Gaza,?including women and children,?as we witness yet another devastating strike?by Israel?on the Al-Taba'een school in Gaza City, sheltering?hundreds?of displaced Palestinians?families, with?scores of fatalities,?amidst continued horror, displacement, and suffering in Gaza," said UN Deputy Spokesperson Farhan Haq.

Violence in Gaza has killed almost 40,000 Palestinians and injured more than 90,000 others, according to the Gaza Ministry of Health.