GENEVA, June 11, 2024 (BSS/AFP) - The UN voiced alarm on Tuesday at the civilian toll of Israel's rescue of four hostages in Gaza, and the fact that Palestinian armed groups are holding captives there.

The United Nations rights office said acts committed by both Israelis and Palestinians "may amount to war crimes".

"We are profoundly shocked at the impact on civilians of the Israeli forces' operation in An Nuseirat at the weekend to secure the release of four hostages," spokesman Jeremy Laurence told reporters in Geneva.

The UN, he said, was also "deeply distressed that Palestinian armed groups continue to hold many hostages, most of them civilians".

Israeli forces stormed Nuseirat refugee camp on Saturday to rescue four Israeli hostages.

Almog Meir Jan, Noa Argamani, Andrey Kozlov and Shlomi Ziv were kidnapped from the Nova festival in southern Israel on October 7.

Hamas-run Gaza's health ministry said at least 274 Palestinians were killed and 698 wounded during the operation.

"Hundreds of Palestinians, many of them civilians, were reportedly killed and injured," Laurence said.

"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."

Asked about figures provided by the Gaza health ministry, he said that prior to October 7, when there was greater possibility to check, the UN had consistently found "the numbers they provide us are... very close to being 100-percent accurate".

The UN rights office has had limited access to verify numbers since the war started but Laurence said it still had contacts on the ground "who are reliable".

- Lives put at 'added risk' -

Asked about hostages held in Gaza, Laurence said this was also "prohibited by international 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," he stressed.

Asked about reports that hostages had been held in civilian locations, he said that should not happen "to an extent they could be ... used as human shields".

"That in itself is a serious breach."

The Gaza war started after Hamas fighters launched an attack on Israel on October 7 which resulted in the deaths of 1,194 people, mostly civilians, according to an AFP tally based on Israeli official figures.

They seized 251 hostages, more than 100 of whom were released during a November truce.

Israel's relentless retaliatory bombing and ground offensive in Gaza has killed at least 37,124 people there, also mostly civilians, according to the health minister in the besieged Palestinian territory.