Leaked secret documents are revealing the systematic scope of mass detention of ethnic minorities in re-education camps in northwestern China.

From 24-hour surveillance, forced ideological lessons and psychological modification, official Communist Party documents from 2017 describe the imprisonment and indoctrination of Uighurs, a predominantly Muslim minority in China's Xinjiang province.

"In my opinion, what we are looking at in Xinjiang is probably the largest internment of an ethno-religious minority since the Holocaust," said Adrian Zenz, a leading researcher on the Uighur crisis and senior fellow in China studies at the Washington-based Victims of Communism Memorial Foundation.

The documents — identified as the China Cables — were obtained, verified and translated by the International Consortium of Investigative Journalists (ICIJ) in collaboration with CBC News and other media organizations around the world.

One of the documents, a 25-point memo approved by Xinjiang's top security official, lays out how best to operate the camps, referred to as "vocational skills education and training centres," as part of the "struggle to fight against terrorism and maintain stability."

China has blamed extremist and separatist groups for many violent domestic attacks in the last two decades. Because of the lack of independent journalism in the country, these attacks and who carried them out have been difficult to verify. It has led to periodic crackdowns in the region, which critics say have culminated in these internment camps.

Workers walk by the perimeter fence of what the Communist Party officially classifies as 'vocational skills education centres' in the Dabancheng district of the Xinjiang region of China on Sept. 4, 2018. (Thomas Peter/Reuters)

Zenz estimates as many as 1.8 million Uighurs are or have been in them over the last three years.

"The significance [of the documents] is that we have an unprecedented insight into what the Chinese government is really doing," Zenz said, "and it gives unprecedented insight also into the priorities."

"And the No.1 priority, besides keeping it secret, is to keep people from escaping."

The first and second points in the memo instruct camp staff to "prevent escape" and say that police "must never allow escapes."

Staff are to "strictly manage door locks and keys" and "strictly manage and control student activities to prevent escapes during class, eating periods, toilet breaks, bath time, medical treatment, family visits, etc."

Uighurs attend a Chinese lesson in what the Communist Party refers to as a 'vocational skills education and training centre' during a tightly controlled government-organized visit in Kashgar, Xinjiang, on Jan. 4, 2019. (Ben Blanchard/Reuters)

The "centres" are instructed to surveil every part of the lives of the "students." Other points in the memo suggest rolling out "secret forces and [bringing] information officers into play to prevent people from joining forces to cause trouble."

The expectation at any of these camps is "full video surveillance coverage of dormitories" and "a 24-hour duty shift system."

Evidence from above

The rigid security details found in the memo are echoed in part by what some observers have seen from satellite imagery.

"It's not a school," said Shawn Zhang, a UBC law school graduate in Vancouver who uses past and present imagery to track buildings he thinks are Chinese re-education camps.

UBC law school graduate Shawn Zhang has used satellite imagery to track changes to Uighur camps in Xinjiang, China, over time. (Paul Émile d'Entremont/CBC)

"The Chinese government claims it is a school," Zhang said while looking at images of one of the first camps he suspected, "But from satellite [images], we can see there is chain-link fencing, maybe topped with razor wire fences. And I can also see the watchtowers, very prison-style watchtowers. It could never happen in real vocational schools."

Zhang's amateur research had him poring over images of cities in Xinjiang looking for signs of construction, allowing him to track changes over time. He has catalogued his findings online in blog posts.

'Repentance and confession'

Beyond security, the operational memo also dictates educational expectations of detainees. The "centres" must "adhere to the daily concentrated study of the national language [Mandarin], law and skills."

All lessons are taught in Mandarin and it "should be gradually used in daily life to communicate," effectively banning the use of any Uighur language. China has been criticized by human rights groups and the U.S. State Department for trying to erase any ethnic identity in these camps other than Han Chinese.

The highly classified documents show that what the Communist Party refers to as 'centres' are designed to surveil every part of the lives of the 'students.' (Thomas Peter/Reuters)

Beyond lessons, a "behaviour management" section sets a "fixed bed position, fixed [line] position, fixed classroom seat and fixed station of work," all of which are "strictly forbidden" to be changed.

The "ideological education" section instructs staff to "bring psychological correction education into play" and "promote the repentance and confession of the students for them to understand deeply the illegal, criminal and dangerous nature of their past behaviour."

The crime of being Muslim

Olsi Jazexhi, an Albanian-Canadian historian at the University of Durres and Elbasan, found out firsthand what "past behaviour" meant.

"They were not extremists. They were not terrorists," said Jazexhi, who studies the history of Islam. "They were normal people who believed in their God and believed in their identity as being Uighurs."

WATCH | 'Propaganda tour' of China camp shocks Albanian-Canadian historian Olsi Jazexhi:

Albanian-Canadian historian Olsi Jazexhi describes a propaganda tour of what the Chinese government calls a 'vocational education training centre' in Xinjiang, China, and how shocked he was at the 'crimes' people were accused of. 1:42

Jazexhi, initially a skeptic of any mistreatment — he thought claims were Western exaggeration — decided to go to see for himself. He arranged to join what he now calls a "propaganda tour" of these camps along with foreign journalists in August.

When he got to Xinjiang, Jazexhi said, he wasn't interested in what his government minders wanted him to see – a cleaned-up school with "students" playing soccer, dancing and learning computer skills. He was told that these were "terrorists" and suicide bombers who needed re-education.

So he started asking students: What is your crime and why are you here?

"The answers that we got was that somebody had prayed to God in public. Another one had put on a hijab. Another one had prayed to God and had asked her mother to join her in prayer, which was also considered to be a crime in China."

Jazexhi said he was shocked and having recorded all of this, uploaded videos to his YouTube channel.

Uighurs worldwide

Beyond details of imprisoning and indoctrinating detainees, another secret document in the China Cables sheds light on how Chinese authorities track and sweep up Uighur populations inside and outside the country.

This document, also from 2017, is a series of guidance "bulletins" from the "Integrated Joint Operations Platform," which Human Rights Watch describes as a "central brain for surveillance in the region."

In numerical detail, a bulletin "from June 19th to 25th" describes how the Chinese government was actively monitoring "24,412 suspicious persons" in Xinjiang and throughout the country at the time.

Uighur security personnel patrol near the Id Kah Mosque in the city of Kashgar in western China's Xinjiang region on Nov. 4, 2017. (Ng Han Guan/Associated Press)

"After conducting verification and handling work, 706 were criminally detained ...15,683 were sent to education and training."

This suggests the infrastructure and personnel needed to round up, transport and detain more than 15,000 people over a week was already in place.

China's changing response

For years, the Chinese government denied the existence of these camps altogether. As visual, anecdotal and testimonial evidence piled up, its narrative changed to one of re-education.

The ICIJ sought comment and sent a copy of the China Cables to the Chinese Embassy in Washington, D.C., both electronically and physically, as well as attempting to reach the Chinese Foreign Ministry in Beijing.

The only official to respond to ICIJ partners about the documents was from Chinese ambassador to the U.K. Liu Xiaoming, who called the reporting "pure fabrication." "They're what we call vocational education training centres," said Liu Xioaming. "They are there for the prevention of terrorism.

"The purpose to set up this training centre is because there are some young people who have … committed minor crimes, not serious enough to be ... sent to prison. So the government gave them opportunity to learn language, Mandarin, to be a good citizen and effective worker."

Demonstrators wave the flag of East Turkestan at a protest to denounce China's treatment of Uighurs in front of the Chinese consulate in Istanbul on July 5, 2018. (Ozan Kose/AFP/Getty Images)

For Zenz, those who come out of these camps aren't gaining skills — they're losing a social identity.

"Probably the No. 1 thing that's taken away is core relationships, because the people are not supposed to talk about what they went through in the camp."

Family members are "too scared" to ask those who were in camps about their experiences for fear of also being sent into a camp, Zenz said.

"The No. 1 thing that's being destroyed by this internment campaign is trust and relationships, the very social fabric of society."

WATCH | Uigurs subjected to mass detention and indoctrination in prison-like camps: