A UN commission has accused Israel of destroying Gaza's health care system through "relentless and deliberate attacks" in its yearlong war with Hamas and said that Palestinian prisoners and Israeli hostages have been tortured and sexually abused.

The expert panel was commissioned in 2021 by the UN-backed Human Rights Council to look into rights violations and abuses in Israel and the Palestinian areas it controls. Led by Navi Pillay, a former UN human rights chief, the panel members are independent experts and do not speak for the world body.

Israel said it firmly rejected the allegations, in a statement from its mission in Geneva.

"This latest report is another blatant attempt by the CoI to de-legitimise the very existence of the State of Israel and obstruct its right to protect its population, while covering up the crimes of terrorist organisations.

"This report shamelessly portrays Israel's operations in terror-infested health facilities in Gaza as a matter of policy against Gaza's health system, while entirely dismissing overwhelming evidence that medical facilities in Gaza have been systematically used by Hamas and the Palestinian Islamic Jihad for terrorist activities," it said.

Israel also rejected accusations of widespread and systematic abuse of Palestinian detainees, amounting to the war crimes and crimes against humanity.

"Israel is fully committed to international legal standards regarding the treatment of detainees. This includes prohibition of excessive use of force and ill-treatment," the mission said.

It accused the commission of creating an "alternate reality", and thereby contributing to "the exacerbation of this conflict".

"We call on states to speak out against this prejudiced approach, which only serves to further stain the credibility of the Human Rights Council and the United Nations at large."

Israeli forces have raided hospitals in Gaza on several occasions, accusing militants of sheltering there. Palestinian medical officials have denied such allegations and accused Israel of recklessly endangering civilians. Hospitals can lose their protection under international law if they are used for military purposes.

The report accused Israel of deliberately killing, detaining and torturing Palestinian medical staff, of targeting their vehicles and of restricting permits for medical evacuations from Gaza. It said those amount to war crimes and crimes against humanity.

"Israel must immediately stop its unprecedented wanton destruction of health care facilities in Gaza," Ms Pillay said in a statement. "By targeting health care facilities, Israel is targeting the right to health itself with significant long-term detrimental effects on the civilian population."

The commission said children have borne much of the cost of such actions, pointing to attacks on medical facilities offering paediatric and neonatal care.

The panel also said it found that thousands of adults and children detained in Gaza had been subjected to "widespread and systematic abuse, physical and psychological violence, and sexual and gender-based violence".

It said Israeli security forces had raped male detainees, attacked their genitals and forced them to perform humiliating or strenuous acts while stripped naked. It said children who had been detained had returned to Gaza unaccompanied and deeply traumatised.

The commission further said the abuse had been institutionalised by Israel's far-right National Security Minister Itamar Ben Gvir. He has boasted of making conditions in the country's prisons as harsh as possible under Israeli law in what he says is an attempt to deter militant attacks.

Israel detained nine soldiers in July over what their defence lawyer said were allegations of sexual abuse of a detainee being held at a shadowy facility where detainees from Gaza have been taken since the start of the war. The lawyer denied the allegations, and their arrest sparked protests by Israeli hard-liners.

The commission also said that hostages held by Palestinian militants in Gaza were subjected to physical and sexual violence, forced isolation and threats, and given limited access to water, food and hygiene facilities. It said Palestinian armed groups were also guilty of war crimes and crimes against humanity, and called on them to immediately release all the hostages.

Hamas-led militants stormed into Israel on October 7, 2023, killing some 1,200 people, mostly civilians, and abducting around 250 others. They are still holding around 100 captives, a third of whom are believed to be dead.

Israel's offensive has killed over 42,000 Palestinians, according to local health authorities, who do not say how many were fighters but say women and children make up more than half of the fatalities. The war has destroyed large areas of Gaza and displaced around 90 per cent of its population of 2.3 million people.

The International Court of Justice is investigating allegations that Israel has committed genocide in Gaza, and the International Criminal Court is considering arrest warrants against Israeli and Hamas leaders. Israel has adamantly denied the accusations and says it abides by international law.

AP/AFP