Palestinians detained by Israel during the Gaza war have largely been held in secret and in some cases subjected to treatment that may amount to torture, the United Nations said on Wednesday.
Since the October 7 Hamas attacks, thousands of Palestinians -- including medics, patients, residents and captured fighters -- have been taken from Gaza to Israel, "usually shackled and blindfolded", the OHCHR UN human rights office said in a report
Thousands more have been detained in the West Bank and Israel, it added.
"They have generally been held in secret, without being given a reason for their detention, access to a lawyer or effective judicial review," OHCHR said.
Israel did not immediately comment but has rejected previous critical reports saying its prisons are run according to international law. The report was released the day after Israel's military police questioned soldiers arrested on suspicion of sexually abusing a Palestinian detainee
At least 53 detainees from Gaza and the West Bank have died in Israeli detention since the Gaza war began on October 7, the report found.
Testimonies for the report suggested that Israel had subjected prisoners to "a range of appalling acts, such as waterboarding and the release of dogs on detainees", UN rights chief Volker Turk said.
The report covers October 7 to June 30. It relies primarily on information gathered through interviews with released Palestinian detainees and other victims and witnesses of violations, OHCHR said.
The report said there were "reasonable grounds to believe" that since October 7, Israel and Palestinian armed groups had "committed gross violations and abuses... of the rights to life, liberty and freedom from torture and other ill-treatment."
These included the use of "rape and other forms of sexual violence," warning the abuses may amount to war crimes.
Besides calling for the abuses to cease, the OHCHR urged all parties to "immediately end all forms of arbitrary detention, including the holding of hostages".
- 'Incommunicado detention' -
The October 7 Hamas attack on southern Israel resulted in the deaths of 1,197 people, mostly civilians, according to an AFP tally based on official Israeli figures.
Militants also seized 251 hostages, 111 of whom are still held captive in Gaza, including 39 the military says are dead.
Israel's retaliatory military campaign in Gaza has killed more than 39,400 people, according to the health ministry in the Hamas-run Palestinian territory, which does not provide details on civilian and militant deaths.
Turk called for the immediate release of all hostages in Gaza, and said all Palestinians arbitrarily detained by Israel must also be set free.
"Secret, prolonged incommunicado detention may also amount to a form of torture," Turk said.
- 'Burnt with cigarettes' -
The report said most Palestinians held since October 7 have been detained "without charges or trial".
Many released Palestinians reported treatment "including severe beatings, electrocution, being forced to remain in stress positions for prolonged periods, or waterboarding".
The report said detainees had been subjected to blackmail, "being burnt with cigarettes, and given hallucinogenic pills".
The report also said the Palestinian Authority "continued to carry out arbitrary detention and torture or other ill treatment in the West Bank, reportedly principally to suppress criticism and political opposition".
A host of studies by rights groups and UN agencies have condemned conditions in Israeli prisons as well as Hamas's treatment of detainees.
Amnesty International said this month it had documented 27 cases of Palestinians, including five women and a 14-year-old boy, who were detained by Israel "for up to four and a half months" without being able to contact their families.
According to the Prisoners Club, a Palestinian rights watchdog, about 9,600 Palestinians are currently in Israeli jails, including hundreds under administrative detention where they can be held for long periods without charge.