Now a report by Adrian Zenz, a German researcher who has exposed China's policies in Xinjiang, says Uighur women, among other ethnic minorities, are being threatened with internment in the camps for refusing to abort pregnancies that exceed birth quotas.
China regularly subjects minority women to pregnancy checks and forces intrauterine devices, sterilisation, even abortion on hundreds of thousands, the interviews and data show.
It coincides with years of restrictions and human rights abuses against Uighurs and other majority-Muslim ethnic groups in China under the authoritarian leadership of Xi Jinping.
Zenz drew from a sizable cache of official documents to compile the report, as well as interviews with former internment camp detainees.
The campaign, he says, likely aimed to sterilise rural minority women with three or more children, as well as some with two children - equivalent to at least 20 per cent of all women of childbearing age.
"Everyone, regardless of whether they're an ethnic minority or Han Chinese, must follow and act in accordance with the law", ministry spokesman Zhao Lijian said Monday.
The report accuses Beijing of engaging in "a policy of Han settler colonialism". An investigation by the BBC in 2019 suggested that children in Xinjiang were being systematically separated from their families in an effort to isolate them from their Muslim communities.
Zenz's research found that population growth in Xinjiang fell drastically with the implementation of forced birth control methods. "In tandem, these three strategies appear to undergird a wider game plan of ethno-racial domination", he said.
In his report, Zenz said his findings represented the strongest evidence yet that Beijing's policies in the autonomous region met one of the genocide criteria cited in the UN Convention on the Prevention and Punishment of the Crime of Genocide, namely "imposing measures meant to prevent births within the group". "To prevent people from having children is wrong", said Omirzakh, who tears up even now thinking back to that day. Dawut says in China, she was forcibly sterilized for having a third child after being released from a Xinjiang detention camp.
Pompeo, a persistent critic of China, including its treatment of Muslims in Xinjiang, said in a statement the findings were consistent with decades of Chinese Communist Party practices "that demonstrate an utter disregard for the sanctity of human life and basic human dignity".
"The Chairs condemn the unacceptable violence against #Uyghur women & call for @UN discussion of crimes against humanity", the tweet said, referring to Senator Marco Rubio, a Florida Republican, and Representative Jim McGovern, a democrat from MA.
In a statement on Monday, the Interparliamentary Alliance on China (IPAC), an global cross-party group of politicians including Conservative MP Iain Duncan Smith, Baroness Helena Kennedy QC and USA senator Marco Rubio, called on the United Nations to "establish an worldwide, impartial, independent investigation into the situation in the Xinjiang region".
A report about forced sterilisations by Chinese authorities, based on a combination of official regional data, policy documents and interviews with ethnic minority women, has prompted calls for a United Nations investigation.
"The findings of this report confirm what many Uyghurs have dreaded for the past three years: the Chinese government is trying to erase us", WUC president Dolkun Isa said in a statement.
China's foreign ministry said in a statement that the act "rudely interferes in China's internal affairs", and urged the U.S. to "immediately correct its mistakes". We have to be direct and honest about what we are experiencing.
Britain said it was aware of reports which "add to our concern about the human rights situation in Xinjiang".
Other observers said the Chinese program is simply a slow-moving form of genocide, as local birth rates are suppressed while Han Chinese migration into Xinjiang is goosed with subsidies and rewards, including reported cash rewards for intermarriage between Han Chinese and Uyghurs.