China's "arbitrary and discriminatory detention" of Uyghurs and other Muslims in its Xinjiang region may constitute crimes against humanity, the outgoing U.N. human rights chief said in a long-awaited report on Wednesday.

U.N. High Commissioner for Human Rights Michelle Bachelet, who some diplomats and rights groups have criticized as soft on China, released the report just minutes before her four-year term ended. She visited China in May.

China has vigorously denied any abuses in Xinjiang and issued a 131-page response to the 48-page U.N. report.

The U.N. Human Rights Office said in the report that "serious human rights violations have been committed" in Xinjiang in the context of the government's application of "counter-terrorism and counter-'extremism' strategies".

"The extent of arbitrary and discriminatory detention of members of Uyghur and other predominantly Muslim groups ... may constitute international crimes, in particular crimes against humanity," the U.N. office said https://www.ohchr.org/en/press-releases/2022/08/un-human-rights-office-issues-assessment-human-rights-concerns-xinjiang on its website.

It recommended the Chinese government take prompt steps to release all those detained in training centres, prisons or detention facilities.

"There are credible indications of violations of reproductive rights through the coercive enforcement of family planning policies since 2017," the office said.

It added that a lack of government data "makes it difficult to draw conclusions on the full extent of current enforcement of these policies and associated violations of reproductive rights."

Rights groups accuse Beijing of abuses against Uyghurs, a mainly Muslim ethnic minority that numbers around 10 million in the western region of Xinjiang, including the mass use of forced labour in internment camps. The United States has accused China of genocide.

U.S. Secretary of State Antony Blinken welcomed the report's release on Thursday, saying in a statement it "deepens and reaffirms our grave concern regarding the ongoing genocide and crimes against humanity" against Uyghurs and other ethnic and religious minority groups. [nL1N30828U]

The European Commission, responding to the report, said it strongly condemns human rights violations in China. EU powerhouse Germany said the report confirmed that "there is cause for grave concern" about gross human rights violations.

A U.N. spokesperson said U.N. Secretary-General Antonio Guterres hopes China will "take on board the recommendations" in the report.

Chinese foreign ministry spokesperson Wang Wenbin described the report as "completely illegal and void".

"This proves once again that the OHCHR has become a thug and accomplice of the U.S. and the West," he said during a regular daily briefing on Thursday in Beijing, where he was asked repeatedly about the report.

U.S. Ambassador to the U.N. Linda Thomas-Greenfield said Washington would work with allies and partners to demand an end to China's abuses. She said it was critical that the full Human Rights Council membership formally discuss the findings of the report as soon as possible and that the perpetrators of the "atrocities" be held accountable.

'UNHELPFUL POLITICIZATION'

Bachelet, who is from Chile, said her report took "considerable work and review" and emerged in the final moments of her tenure because she wanted to deal with input from the Chinese government last week.

"Dialogue and engagement is about trying to build trust - incrementally - even when it seems unlikely. My own experience in Chile showed me the value of this approach," she said."To be perfectly honest, the politicization of these serious human rights issues by some States did not help," she added. "They made the task more difficult, they made the engagement more difficult and they made the trust-building and the ability to really have an impact on the ground more difficult."

Dilxat Raxit of the World Uyghur Congress, an international organisation of exiled Uyghur groups, said the report confirmed "solid evidence of atrocities" against Uyghurs, but wished it had gone further.

"I regret that the U.N. Office of the High Commissioner for Human Rights did not characterise these extreme atrocities in China as genocide," he told Reuters in an email.

Reuters reported last month that China had asked Bachelet to bury the report.

Bachelet, 70, plans to return to Chile to retire. No successor has been appointed yet.

Human rights activists hailed the report but said its timing undermined its impact.

"She put out the report - which was her job - but avoided the aftermath. It doesn't show the necessary leadership on how to take this forward," said Olaf Wientzek, director of the Geneva office of the German Konrad Adenauer Foundation.