A new leak of highly classified Chinese government documents detail China’s manual for running mass detention camps holding hundreds of thousands of Uighur Muslims and other minorities in the Xinjiang region. The International Consortium of Investigative Journalists’ Bethany Allen-Ebrahimain, a former national security reporter for The Daily Beast, obtained the “China Cables.” The cables include a nine-page memo sent out in 2017 by Zhu Hailun, then deputy-secretary of Xinjiang’s Communist Party and the region’s top security official, to those who run the camps. The memo details a classified list of guidelines, personally approved by the security official, which say the camps should be run as high security prisons, with strict discipline, punishments, and “no escapes.” China’s U.K. ambassador, Liu Xiaoming, called the documents “pure fabrication and fake news.”

Other documents from the leak reveal how the Chinese government uses mass surveillance and a predictive-policing algorithm that analyzes personal data. One document shows how the system flagged 1.8 million people simply because they had a data sharing app, Zapya, on their phone. A memo also says detainees will only be released from the camps when they demonstrate they have transformed their beliefs and language. “Promote the repentance and confession of the students for them to understand deeply the illegal, criminal, and dangerous nature of their past activity,” the BBC quotes the memo as saying.