Palestinians in the Israeli occupied West Bank and East Jerusalemare suffering a drastically worsening human rights environment, alongside “unconscionable death and suffering” in the Gaza Strip, the U.N. human rights chief said on Tuesday.

“The situation in the West Bank, including East Jerusalem, is dramatically deteriorating,” Volker Turk, U.N. High Commissioner for Human Rights, told the opening session of the U.N. Human Rights Council.

The West Bank, where the internationally recognised Palestinian Authority exercises limited self-rule under Israeli occupation, has seen the worst unrest for decades, in parallel with the war in the Gaza Strip, which is controlled by Hamas.

Turk said that from the start of the Gaza war in October through mid-June, 528 Palestinians, 133 of them children, had been killed by Israeli security forces or settlers in the West Bank, in some cases raising “serious concerns of unlawful killings”.

Twenty-three Israelis have been killed in the West Bank and Israel in clashes with or attacks by Palestinians, he said.

In Gaza, Turk said he was “appalled by the disregard for international human rights and humanitarian law” by parties to the war.

“Israel’s relentless strikes in Gaza are causing immense suffering and widespread destruction, and the arbitrary denial and obstruction of humanitarian aid have continued,” Turk said.

“Israel continues to detain arbitrarily thousands of Palestinians. This must not continue.”

He added that Palestinian armed groups were continuing to hold hostages, including in populated areas, which put both the hostages and civilians at risk.

Israel’s permanent mission to the U.N. in Geneva accused Turk of “completely omitting the cruelty and barbarity of terrorism” in his address to the U.N. Human Rights Council.

“Hostilities in Gaza are the direct result of Hamas terrorism, decades of rocket-fire and incitement against the Jewish people and the State of Israel, culminating in its brutal attacks against Israel on October 7,” the diplomatic mission said in a statement.

Israel’s ground and air campaign was triggered when Hamas-led militants stormed into southern Israel on Oct. 7, killing around 1,200 people and seizing more than 250 hostages, according to Israeli tallies.

Israel’s offensive has killed more than 37,400 people in Gaza, according to its health authorities, and left much of the enclave’s population homeless.