The UN report detailing serious rights abuses by China in its Xinjiang region found possible crimes against humanity but not genocide — an atrocity crime tough to prove in international law.

As the fall-out from the report continues to reverberate on Saturday, some countries are considering how they can take the findings further.

The crime of genocide covers not just acts to destroy a particular group but also, critically, a second component: proven intent.

Nikita White, of Amnesty International Australia, told AFP that the UN report's conclusions were "really strong and really serious".

However, "to allege genocide, the UN would need to prove intent. And that's really difficult… when access to Xinjiang is restricted".

Available information

Campaigners have long accused China of a litany of abuses in the far-western region, including detaining more than one million Uyghurs and other Muslims, and forcibly sterilizing women.

And the United States and lawmakers in other Western countries have meanwhile openly accused China of committing genocide against Xinjiang minorities.

There were hopes that the UN findings would lend additional credibility to such charges, vehemently rejected by Beijing.

The long-awaited UN report did document a string of violations, finding that torture allegations were credible, cited forced medical treatment and said a substantial proportion of the Muslim population had been put through so-called Vocational Education and Training Centers.

The extent of arbitrary and discriminatory detention "may constitute international crimes, in particular crimes against humanity", it said.

Crimes against humanity rank along with genocide and war crimes as atrocity crimes in international law.

But the report did not mention the word genocide, something Beijing was quick to latch onto.

"Even this illegal report with no credibility does not dare to exaggerate the so-called fallacies of genocide," China's foreign ministry said.

UN rights office spokeswoman Ravina Shamdasani stressed that "we are making no judgment ourselves on that specific issue".

"The available information assessed according to our own standards does not enable us to do so at this time," she told AFP.

But for US Secretary of State Antony Blinken, the report "deepens and reaffirms our grave concern regarding the ongoing genocide".

Where to go next is sure to come up at the UN Human Rights Council session, starting on September 12.

'Intent to destroy'

The Convention on the Prevention and Punishment of the Crime of Genocide, adopted after World War II, codified criminal genocide for the first time.

It was the first human rights treaty adopted by the UN General Assembly, in 1948.

It defines "acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group".

That could be through killing members of the group, but also through other methods, including measures to prevent births, forcibly transferring children, or deliberately inflicting living conditions aimed to physically destroy a group.

However, the definition comprises not just the acts committed, but also the intent, which "is the most difficult element to determine", according to a UN factsheet on the convention.

"Cultural destruction does not suffice," it says.

"It is this special intent … that makes the crime of genocide so unique."

Report details population change

While the report did not refer to genocide, it did document population shifts in the region, using Chinese official figures.

Outnumbered more than 10 to one in 1953, the Han Chinese are now at near parity with the Uyghurs, largely due to westward migration, including as a result of government incentives.

The report detailed recent changes in birth control policy that allowed the Han in Xinjang greater reproductive rights than before, and documented the "unusual and stark" halving of the birth rate in the region, notably among the Uyghurs.

It also remarked upon the "unusually sharp rise" in the sterilization rate in the region, which is more than seven times the average across China.

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

It also noted that the controversial VETCs were set up in the region to, in China's words, "eradicate the breeding ground" for the spread of religious extremism.

Genocide risk?

The UN Office on Genocide Prevention, based in New York, assesses whether there is risk of atrocity crimes occurring in a particular situation, with the objective of preventing or halting such crimes.

The Uyghur Human Rights Project advocacy NGO wants the office to conduct an immediate risk assessment — including of genocide — following the report.

"Although (the report) doesn't say genocide, I think the Uyghur groups or the researchers would call it genocide," the group's Peter Irwin told AFP.