- Mon, 03/20/2017 - 16:01
18 March 2017 Last updated at 00:09 GMT
China says Islamist separatists in Xinjiang are the greatest threat to national security. The far western region is home to a community of some 10 million Uighurs, who are mostly Muslim.
Beijing is concerned that young Uighurs are vulnerable to radicalisation. Widespread intimidation makes reporting from the region extremely difficult, but the BBC gained exclusive access to the area.
Filmed and edited by Matthew Goddard; Produced by Ashley Semler