Palestinian officials say Israeli forces killed 274 people during the operation to rescue four captives held in Gaza.

At least 274 Palestinians were killed during the raid on Saturday, according to Gaza health officials, as Israeli forces rescued four captives held in Gaza for more than eight months.

The rare daylight raid was carried out by heavily armed Israeli special forces with air support.

More than 600 people were injured in the raid, including children and women, according to Palestinian officials. The influx of patients since the raid has overwhelmed hospitals in the enclave, which were already operating with limited supplies of medicine, food and fuel.

Jeremy Laurence, a spokesman for the office of UN High Commissioner for Human Rights Volker Turk, said on Tuesday that the office is “profoundly shocked” at the impact of the Israeli assault on civilians.

“The manner in which the raid was conducted in such a densely populated area seriously calls into question whether the principles of distinction, proportionality and precaution – as set out under the laws of war – were respected by the Israeli forces,” he said in a statement.

“Our Office is also deeply distressed that Palestinian armed groups continue to hold many hostages, most of them civilians, which is prohibited by international humanitarian law. Furthermore, by holding hostages in such densely populated areas, the armed groups doing so are putting the lives of Palestinian civilians, as well as the hostages themselves, at added risk from the hostilities.”

Laurence said Turk welcomed the UN Security Council resolution passed on Monday to endorse a US-backed Gaza ceasefire proposal and said all parties must ensure the “unfettered flow of humanitarian aid”.

Hamas said in a statement on Tuesday that it endorses the UN resolution and it was ready to cooperate with mediators to enter more indirect negotiations over its implementation.

This was the second ceasefire resolution passed by the Security Council, which had in March also voted in favour of a resolution that called for an immediate ceasefire, but it has not been implemented.

At least 37,164 people have been killed and 84,832 injured since the start of the war on October 7, according to the Palestinian Ministry of Health in Gaza.