New satellite images are said to show a facility used to detain China's Uighur Muslim ethnic minority in the western region of Xinjiang.

Shawn Zhang, a law student in Canada, posted what he said were images of a reeducation camp in Kashgar, Xinjiang, saying they showed that by August it had expanded to more than 11 times its size in February 2017.

People say they've witnessed or been subjected to physical and psychological torture in camps like this.

Newly published satellite images are said to show the rapid expansion of a Chinese facility built for the country's persecuted Uighur Muslim ethnic minority.

Shawn Zhang, a law student in Canada, on Wednesday posted what he said were photos of a reeducation camp in the western region of Xinjiang, where about 8 million Uighurs live and are mostly detained. Many Uighurs refer to the region as East Turkestan.

Zhang said the photos showed a reeducation camp in southern Shule, a county near Xinjiang's capital, Kashgar.

The facility was about 28,000 square meters in February 2017 and by this August had grown to more than 11 times that size, to 320,000 square meters, according to Zhang's measurements.

The GIF below shows the facility in February 2017, August 2017, June 2018, and August 2018.

The dramatic expansion of the Kashgar camp appears to be a sign of China's growing crackdown on the Uighur people, as more and more have been imprisoned in detention camps or reeducation centers.

Read more: Here are all of Business Insider's stories on Beijing's repression of Uighur people in China.

Rights activists have accused China of keeping 1 million Uighurs in such camps. And the number may be growing — Radio Free Asia this week described unnamed regional authorities as saying they had to transfer inmates out of Xinjiang to other regions across China because, one said, "we are experiencing an overflow of inmates."

Hu Lianhe, a senior Communist Party official, has claimed that there are "no such things as reeducation centers" but acknowledged that the government had detained people it considers extremists. Beijing justifies its surveillance of Uighurs as a counterterrorism measure.

Police patrol on a scooter as an ethnic Uighur boy stands in his doorway in Kashgar in June 2017. Kevin Frayer/Getty Images

Uighurs who have been inside those camps have described witnessing and experiencing physical and psychological torture, including being shackled to a chair, beaten up, and deprived of sleep.

Others have described seeing detainees being forced to sing patriotic songs about Chinese President Xi Jinping in order to be fed.

Zhang has long been critical of the Chinese state and has used satellite imagery to identify and track potential camps throughout Xinjiang.

His family, who live in China, have previously been contacted by police about his critical posts on social media.