Chinese Muslim students returned home for university holidays to find members of their families had been taken away for “unhealthy thoughts”, leaked government documents show.

Young people from the minority ethnic Uighur community in the Xinjiang province were told their loved ones were undergoing “training”, which is why they were not at home, The New York Times revealed after receiving 400 pages of internal documents.

Local officials were instructed to meet students on arrival to explain their relatives were susceptible to Islamic extremism and had been detained “for their own good”, according to the papers.

“No matter what age, anyone who has been infected by religious extremism must undergo study,” read one of the responses in a scripted Q&A-style guide for officials in Turpan, southern Xinjiang, on how to respond to worried students’ questions.

China destroying Uighur burial grounds Show all 6 1 /6 China destroying Uighur burial grounds China destroying Uighur burial grounds Teywizim cemetery in Hotan (before and after) China is destroying burial grounds where generations of Uighur families have been laid to rest, leaving behind human bones and broken tombs in what activists call an effort to eradicate the ethnic group's identity Earthrise/AFP/Getty China destroying Uighur burial grounds A cemetery in Xayar (before and after) This combo of satellite images received on September 30, 2019 from CNES 2019, distributed by Airbus DS and produced by Earthrise shows a picture from August 29, 2017 (top) showing a cemetery (C) and the same view on July 5, 2019 (bottom) with no sign of the facility in Xayar, Xinjiang province. - China is destroying burial grounds where generations of Uighur families have been laid to rest, leaving behind human bones and broken tombs in what activists call an effort to eradicate the ethnic group's identity in Xinjiang. (Photo by Handout / various sources / AFP) / TO GO WITH China-rights-Xinjiang,FEATURE by Eva Xiao, Pak Yiu, with Andrew Beatty -----EDITORS NOTE --- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CNES 2019/ DISTRIBUTION AIRBUS DS/ PRODUCED BY EARTHRISE" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVES / (Photo by HANDOUT/EARTHRISE/AFP via Getty Images) HANDOUT Earthrise/AFP/Getty China destroying Uighur burial grounds A graveyard in Aksu (before and after) An image of a graveyard in Aksu in 2015, where Uighur poet Lutpulla Mutellip was buried and the same view in 2018 and then again in 2019 showing a new park called "Happiness Park" Earthrise/AFP/Getty China destroying Uighur burial grounds A cemetery in Xayar (before and after) This combo of satellite images received on September 30, 2019 from CNES 2019, distributed by Airbus DS and produced by Earthrise shows a picture from August 29, 2017 (top) showing a cemetery (C) and the same view on July 5, 2019 with no sign of the facility in Xayar, Xinjiang province. - China is destroying burial grounds where generations of Uighur families have been laid to rest, leaving behind human bones and broken tombs in what activists call an effort to eradicate the ethnic group's identity in Xinjiang. (Photo by Handout / various sources / AFP) / TO GO WITH China-rights-Xinjiang,FEATURE by Eva Xiao, Pak Yiu, with Andrew Beatty -----EDITORS NOTE --- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CNES 2019/ DISTRIBUTION AIRBUS DS/ PRODUCED BY EARTHRISE" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVES / (Photo by HANDOUT/EARTHRISE/AFP via Getty Images) HANDOUT Earthrise/AFP/Getty China destroying Uighur burial grounds Sulanim cemetery in Hotan (before and after) This combo of satellite images received on September 30, 2019 from CNES 2019, distributed by Airbus DS and produced by Earthrise shows a picture from April 24, 2018 (top) showing the Sulanim cemetery (C) in Hotan, Xinjiang province and the same view on August 6, 2019 (bottom) with no sign of the facility and it has been replaced with a car park. - China is destroying burial grounds where generations of Uighur families have been laid to rest, leaving behind human bones and broken tombs in what activists call an effort to eradicate the ethnic group's identity in Xinjiang. (Photo by Handout / various sources / AFP) / TO GO WITH China-rights-Xinjiang,FEATURE by Eva Xiao, Pak Yiu, with Andrew Beatty -----EDITORS NOTE --- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CNES 2019/ DISTRIBUTION AIRBUS DS/ PRODUCED BY EARTHRISE" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVES / (Photo by HANDOUT/EARTHRISE/AFP via Getty Images) HANDOUT Earthrise/AFP/Getty China destroying Uighur burial grounds A cemetery in Xayar (before and after) This combo of satellite images received on September 30, 2019 from CNES 2019, distributed by Airbus DS and produced by Earthrise shows a picture from August 20, 2014 (top) showing a cemetery (centre L) and the same view (bottom) on July 5, 2019 where it has been replaced with a a newly built standardised cemetery, in Xayar, Xinjiang province. - China is destroying burial grounds where generations of Uighur families have been laid to rest, leaving behind human bones and broken tombs in what activists call an effort to eradicate the ethnic group's identity in Xinjiang. (Photo by Handout / various sources / AFP) / TO GO WITH China-rights-Xinjiang,FEATURE by Eva Xiao, Pak Yiu, with Andrew Beatty -----EDITORS NOTE --- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / CNES 2019/ DISTRIBUTION AIRBUS DS/ PRODUCED BY EARTHRISE" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVES / (Photo by HANDOUT/EARTHRISE/AFP via Getty Images) HANDOUT Earthrise/AFP/Getty

Many Uighurs from Xinjiang go to university outside the region, where the clampdown on the minority Muslim community has been focused.

In the leaked guide, officials were told to inform students their families “are in a training school set up by the government to undergo collective systematic training”.

They are advised to placate any worries by insisting the disappeared are in good hands, even though they cannot leave their “schools” and cannot be visited. “You have absolutely no need to worry about how they are doing,” the document told officials to say.

“Tuition for their period of study is free and so are food and living costs.” It advised informing the students that the government spends $3 (£2.30) per day for each person’s daily meals.

However, if a student is agitated or continues asking pressing questions, the set answers become less reassuring and more assertive, The New York Times explained.

They are told release depends on a points-based system and relatives will have to stay longer if their free family member does anything to stop them gaining points, such as spreading rumours, the documents reveal.

The guide claims their studies will not be affected if family members earn money by working on the farm. The government claims it will help with fees, and that loans and a “poverty allowance” are available.

Students are told their relatives are not criminals, but “their thinking has been infected by unhealthy thoughts” and “freedom is only possible when the ‘virus’ in their thinking is eradicated”.

In response to any questions about why their relative cannot “train” at home, they are told to respond: “If you weren’t thoroughly cured, as soon as you returned home you would infect your family with this virus, and your whole family would fall ill.”

China has maintained the Muslim minority group visit voluntary “training centres”, which aim to combat terrorism and extremism, after a string of attacks were carried out in the Xinjiang region.

However, the mass detention of Uighurs and ethnic Kazhak and Uzbek Muslims since 2017 has been condemned by other nations as a human rights issue.

Other leaked documents show having a long beard, not drinking or smoking and learning Arabic were listed as reasons why a person should be detained because they hint at radicalisation or anti-government beliefs.

They also include private speeches by Xi Jinping and internal reports on party dissenters over the crackdown, offering an unusual insight into the heavily guarded operation.

The scripted interaction with returning family members forms an attempt to control how the rest of China views the removal of Uighurs from the community.

“Returning students from other parts of China have widespread social ties across the entire country,” one of the documents seen by The New York Times said.