Chinese authorities are using a mobile app designed for mass surveillance to profile, investigate and detain Muslims in Xinjiang by labelling “completely lawful” behavior as suspicious, a Human Rights Watch (HRW) report revealed.

Beijing had come under international criticism over its policies in the northwest region of Xinjiang, where as many as 1 million Uighurs and other mostly Muslim minorities were being held in internment camps, according to a group of experts cited by the United Nations.