To detain thousands of people in short order, the government repurposed old schools and other buildings. Then, as the number of detainees swelled, in 2018 the government began building new facilities with far greater security measures and more permanent architectural features, such as heavy concrete walls and guard towers, the BuzzFeed News analysis shows. Prisons often take years to build, but some of these new compounds took less than six months, according to historical satellite data. The government has also added more factories within camp and prison compounds during that time, suggesting the expansion of forced labor within the region. Construction was still ongoing as of this month.

“People are living in horror in these places,” said 49-year-old Zhenishan Berdibek, who was detained in a camp in the Tacheng region for much of 2018. “Some of the younger people were not as tolerant as us — they cried and screamed and shouted.” But Berdibek, a cancer survivor, couldn’t muster the energy. As she watched the younger women get dragged away to solitary confinement, “I lost my hope,” she said. “I wanted to die inside the camp.”

BuzzFeed News identified 268 newly built compounds by cross-referencing blanked out areas on Baidu Maps — a Google Maps–like tool that’s widely used in China — with images from external satellite data providers. These compounds often contained multiple detention facilities.