BEIJING - China has built more than 1,000 internment camps for ethnic Uyghurs and other Muslims in the Xinjiang Uyghur Autonomous Region (XUAR), one of the world's foremost experts on mass incarcerations in the region told RFA.

Adrian Zenz, a lecturer in social research methods at the Germany-based European School of Culture and Theology, recently told RFA's Uyghur Service he is reviewing official documents and other sources of information to determine a maximum estimate for those held in a network of camps that he said likely number more than 1,000 in the XUAR.

"Maximum estimates are inherently speculative and I'm trying to be quite cautious in my estimate, but I'm currently looking at the details of that," he said.

"I'm increasingly viewing evidence that would indicate that my original estimate of at least one camp per administrative unit between township and prefecture levels, which adds up to 1,200, was accurate. I'm increasingly moving in the direction that it's over 1,000 camps."

Since April 2017, authorities in the XUAR have held Uyghurs and other Muslim minorities accused of harboring "strong religious views" and "politically incorrect" ideas in a vast network of camps in the region.

Zenz had initially estimated that some 1.1 million people are or have been detained in the camps, but in March this year revised his assessment to 1.5 million–equivalent to just under 1 in 6 members of the adult Muslim population of the XUAR.

While Beijing once denied the existence of the camps, China this year changed tack and began describing the facilities as "boarding schools" that provide vocational training for Uyghurs, discourage radicalization, and help protect the country from terrorism.

Reporting by RFA's Uyghur Service and other media organizations, however, has shown that those in the camps are detained against their will and subjected to political indoctrination, routinely face rough treatment at the hands of their overseers, and endure poor diets and unhygienic conditions in the often overcrowded facilities.

Shifting strategy

According to Zenz, China significantly increased its internment and internment capacity in the XUAR in 2018, but gradually shifted from "vocational training" into what he called "involuntary or coercive forms of labor" in the second half of last year.

"I think these movements are gradual, but I think they are probably accelerating as we speak," he told RFA.

Zenz said that while it is difficult to confirm such trends, as there is limited evidence to work from and China's government doesn't provide statistics, he believes that "in 2019 Xinjiang has been moving from internment into forced labor."