The United Nations human rights chief on Tuesday warned that the rights situation in the West Bank is rapidly deteriorating, while there had been "unconscionable death and suffering" in Gaza.

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

He said 528 Palestinians, 133 of them children, were killed by Israeli military forces or settlers from the start of the current war on Gaza in October to June 15, “in many cases raising serious concerns of unlawful killings”.

Turk said he was "appalled by the disregard for international human rights and humanitarian law" by parties of the conflict in Gaza.

"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."