Human rights groups previously estimated that as many as one million people have been held in the camps
, which satellite photos show have sprung up across the region in recent months.
Along with restrictions on halal food, Islamic dress, and general religiosity, the ongoing crackdown has primarily affected the Uyghurs, a predominantly Muslim ethnic group who historically were the majority in the region.
Chinese Foreign Ministry spokesman Lu Kang defended recent measures at a press briefing Thursday, saying "taking measures to prevent and crack down on terrorism and extremism have helped preserve stability, as well as the life and livelihood of people of all ethnicities in Xinjiang."
While the strategies Beijing is taking are new -- and include a state-of-the-art surveillance regime -- they echo a longtime paranoia about Xinjiang and a deep suspicion of its non-Han population among China's rulers which have historically resulted in oppression and rebellion.
is vast. Stretching 1.6 million square kilometers (640,000 sq miles) from the Tibetan plateau in the southeast to Kazakhstan on its north-western border, it is by far China's largest administrative region, but one of its least densely populated. Around 22 million people reside in the region, most of whom live around the major cities of Urumqi, Kashgar and Yining.
While Chinese armies rampaged through what is now Xinjiang and controlled parts of it for centuries, the modern administrative unit only dates to
the mid-nineteenth century, a fact hinted at by its name, which translates as "new frontier" in Chinese.
Despite the Communist Party's claims
that "Xinjiang has since ancient times been an inseparable part of the motherland," the relatively recent imperial conquest of Xinjiang has always been accompanied by an ever present paranoia that it could break away from Chinese rule, becoming another "Outer Mongolia."
During the Sino-Soviet split
, there was a deep fear in Beijing that Moscow would seek to annex Xinjiang, which bordered the then Soviet Union, or encourage ethnic minority groups to rebel.
This was a very real possibility: during the 1930s and 40s, as the short-lived Nationalist government fought a civil war with the Communists and faced a growing threat of Japanese invasion, two br