With China accused of detaining hundreds of thousands of Uighur Muslims without trial in its western province of Xinjiang, a BBC investigation analyzed satellite data to determine that the detention camp system in the region is rapidly expanding. Reviewing images from the European Space Agency's Sentinel satellite service, the BBC finds at least 40 such facilities across Xinjiang, half built within last two years—with a big thrust of construction just in the past six months. Among the largest is a "massive, highly secure compound" still being built at Dabancheng, about an hour's drive from the provincial capital, Urumqi. It is enclosed within a two kilometer-long exterior wall punctuated by 16 guard towers.

A BBC team dispatched to visit the site saw a "mini-city sprouting from the desert and bristling with cranes." But they were followed from Urumqi by a convoy of security personnel. As they approached the camp, their car is stopped; they were ordered to turn off their cameras and to leave.

The UN has cited estimates that over one million Uighurs have been detained, with no charges or due process. The total Uighur population in Xinjiang is around 10 million. Survivors of the camps interviewed by the BBC, now exiled in Turkey, said that any expression of Muslim identity is enough to result in detention. While mosques continue to function in the region, public-sector employees are reported to be barred from attending, or from fasting for Ramadan. The general population, even in remote villages, has come under strict surveillance, to determine who should be detained.

But such survivor testimonies are likely to become more rare—both because terms of detention now seem to be basically indefinite, and because severe travel restrictions are being imposed on Xinjiang residents, with all passports reportedly confiscated by the police for "safe keeping."

From denial to spin control
After denying the existence of the camps for months, Chinese authorities are now openly acknowledging them, and attempting to portray them in positive terms, calling them "vocational schools" that combat "terrorism and religious extremism." Shohrat Zakir, party chairman for Xinjiang (and himself an ethnic Uighur), told state media the facilities are "humane," and also stressed their effectiveness: "In the past 21 months, no violent terrorist attacks have occurred and the number of criminal cases, including those endangering public security, has dropped significantly. Xinjiang is not only beautiful but also safe and stable."

Zakir said that "students" in the facilities are provided with free meals, air-conditioned dormitories, movie screenings, and access to computer rooms. "Xinjiang has launched a vocational education and training program according to the law. Its purpose is to get rid of the environment and soil that breeds terrorism and religious extremism."

An AFP report claims evidence that some 180 such facilities have been built in Xinjiang since 2014, and cites documentation that local authorities are stocking up instruments of repression—presumably for use in the camps. For instance, just this year Hotan prefecture made purchases of 2,768 police batons, 550 electric cattle prods, 1,367 pairs of handcuffs, and 2,792 cans of pepper spray. 

Restrictions imposed on Uighurs even outside the camps are also escalating fast. ChinaFile cites claims that volunteers euphemistically called "relatives" have been mobilized tp occupy the homes of some 1 million Uighurs in Xinjiang as "guests," subjecting their hosts to indoctrination in "counter-extremism" and party loyalty. A New York Times account renders these volunteers as "big brothers" or "big sisters," and they are apparently overwhelmingly Han Chinese.

Trump administration complicit
And the Trump administration appears to be complicit in silencing criticism of the mass detention in Xinjiang. One outspoken former detainee who was invited to testify before Congress about his ordeal was denied a visa to enter the United States. Omir Bekali, an ethnic Kazakh who became a citizen of Kazakhstan after emigrating there in 2006, was detained last year while visiting his parents in the Xinjiang village of his birth.

After several months in jail, apparently without charge, he was transfered to a camp near the city of Karamay, where was held another 20 days before being released on the intercession of Kazakh authorities. He told the Washington Post he considered suicide at the Karamay camp, where detainees were subject to ritual humiliations—even forced to consume pork and alcohol, in violation of their Muslim beliefs.

Bekali was invited to Washington in September by the chairs of the Congressional-Executive Committee on China. But his visa application was rejected by the US consulate in Istanbul. "Why did they invite me and then reject my visa?" Bekali said to The Guardian by phone from Turkey. "I've received so many threats after speaking out, I feel like they should be able to do at least this simple request."