Xinjiang, China’s most impoverished region, is home to 12 million Uighurs, most of whom are Muslims. The Chinese state is currently engaged in a campaign to quell separatist views among some Uighurs, while forcibly integrating the general population into mainstream Chinese culture through a state-run program of forcible assimilation. It is believed that at least a million Uighurs are currently living in detention camps run by the Communist Party of China, ostensibly for “re-education”. Xinjiang is often referred to as the world’s most heavily surveilled region.

According to the BBC’s Panorama program, patents filed by Chinese companies point to the development of facial recognition programs that can distinguish subjects by ethnicity, and appear to be “specifically designed to identify Uighur people”. Among them are artificial intelligence systems that are able to detect facial micro-expressions, so as to analyze the emotions of subjects. According to Panorama, some systems even monitor “minute changes” in skin pores on the face of subjects, as a means of detecting micro-expressions. The software then allegedly produces a pie chart that details a subject’s state of mind.

The BBC said it reached out to the Chinese embassy in London, which claimed to have “no knowledge” of these alleged surveillance programs. In a statement issued on Tuesday, the Chinese embassy said that “the political, economic and social rights and freedom of religious belief in all ethnic groups in Xinjiang are fully guaranteed”. It added that people in Xinjiang “live in harmony and enjoy a stable and peaceful life with no restriction to personal freedom”.