In the last two years, a growing body of testimony by former Xinjiang residents and a trove of government procurement documents, directives and state media reports have painted a picture of oppression in the region, where Chinese authorities have relied on far-reaching electronic surveillance to help dictate its mass internment program.

New York-based Human Rights Watch said Thursday it gained a new level of insight into precisely what information the Chinese government collects by examining a mobile app that Xinjiang officials use to input data into a database called the Integrated Joint Operations Platform.

The IJOP system, which keeps track of practically the entire Xinjiang population, alerts authorities when a person unexpectedly crosses virtual "fences" by driving past a certain checkpoint or checking into a hotel, according to the rights group.