The Chinese government made the unexpected announcement Tuesday that it had released most of the minority Muslims being held in controversial internment camps across the country’s Xinjiang region. Two regional leaders told the media that as many as 90 percent of the ethnic Muslims being held had left the so-called reeducation camps, been given jobs, and “returned to society.” The government has offered no evidence of the release and has long refused to provide much information about the heavily guarded camps that have sparked international condemnation. Experts estimate the number of minority Muslims interned in Xinjiang tops 1 million.

The abrupt announcement comes as international criticism has ratcheted up over Beijing’s sweeping detentions in the region to stamp out simmering separatist aspirations and assimilate the some 12 million ethnic Uighurs living there. During a press conference Tuesday, government officials toed the line from Beijing insisting that the camps were vocational training centers, going so far as to call the detainees “students.” “Tuesday’s briefing—which was paired with an exhibition profiling Xinjiang as a travel destination and featuring performances by ethnic-minority musicians and dancers in traditional garb—is part of China’s campaign to counter Western-led criticism of its treatment of Muslims in Xinjiang,” the Wall Street Journal reports.

“Gathering evidence to test their claims of numerous releases from the camps is likely to be difficult,” the New York Times reports. “Foreign journalists are closely monitored and controlled when they visit Xinjiang, and independent investigators and human rights groups do not have free access.”