June 11 (UPI) — The U.N. Human Rights Office said Tuesday that Israel’s hostage rescue operation in Gaza may have been indiscriminate, disproportionate and negligent in a such densely populated area, potentially constituting a war crime.

Expressing profound shock at the reported deaths and wounding of hundreds of Palestinians in Saturday’s operation in Nuseirat to extract four Israelis being held by Hamas, OHCHR spokesman Jeremy Laurence said the mission “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.”

However, the OHCHR stressed that the actions of Palestinian armed groups may also constitute war crimes, calling their ongoing holding of hostages, most of them civilians in contravention of international humanitarian law, “deeply distressing.”

“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.

“All these actions, by both parties, may amount to war crimes,” he added.

The Hamas-run Gaza Health Ministry said Sunday said that at least 274 people had been killed and 698 injured in what it said was a massacre in the Nuseirat refugee camp.

At least 64 children, 57 women and 37 people considered elderly were among those killed.

Shlomi Ziv, 40; Almong Meir Jan, 21; Andrey Kozlov, 27; and Noa Argamani, 25; were freed by Israeli special forces eight months after being abducted from the Nova Music Festival in southern Israel during the Oct. 7 attacks.

The three men and the woman, Noa Argamani, were pronounced by Israeli doctors who examined them after arriving back on Israeli soil to be in good condition, medically, but malnourished.

Their rescue brings to seven the number of hostages freed in special operations but around 120 continue to be held by Hamas and other armed groups.

The warning to both sides followed U.N. Security Council backing of a U.S.-drafted cease-fire resolution Monday that also called for the immediate release of all hostages including the remains of those deceased, and the exchange of Palestinian prisoners.

Welcoming the international community’s unified call for a “full and complete ceasefire,” Human Rights High Commissioner Volker Turk said ensuring “the full and unfettered flow of humanitarian aid to the desperate population of Gaza,” had to be an immediate priority.

“The High Commissioner calls on all parties as well as third States, in particular those with influence over the parties to the conflict, to also maximize efforts to work towards the goal whereby Israelis and Palestinians can fully enjoy all human rights and live side by side, in peace,” said the release.

The developments came as U.S. Secretary of State Antony Blinken began his eighth visit to the region as part of efforts by Washington to get Israel and Hamas to agree to a deal leading to a cessation of hostilities and the release of hostages.

Blinken will visit Egypt, Israel, Jordan and Qatar to push for an agreement around a 3-stage plan to end the war laid out by U.S. President Joe Biden on May 31, according to State Department spokesman Matthew Miller.

The proposal is currently in the hands of Hamas leaders, delivered via Qatari mediators, but the group which is designated as a terrorist organization by the United States and many other nations has yet to respond.