In the Chinese government's vast network of re-education camps in Xinjiang province, the daily horror of internment was infused with monotony and boredom. Detainees were forced to endure countless hours of indoctrination and language classes, perched on small stools. In some facilities, they had to watch TV propaganda broadcasts praising President Xi Jinping for hours on end.

The slightest infraction, such as a whispered conversation, was met with swift and harsh punishment.

But among the many months spent locked up, some former detainees report that one day was different: The day when they were forced to pick one or several infractions from a list they were handed. In essence, the detainees had to retroactively choose the crimes for which they had been imprisoned, often for months, in most cases without being told why they had been detained in the first place.

DW spoke to four former detainees, two men and two women from Xinjiang, a remote region in northwestern China whose mostly Muslim population has long faced repression by the Chinese authorities — including, in recent years, lengthy internment in re-education camps. The Chinese government claims the camps were set up to fight extremism and provide Uighurs with vocational skills. But detainees and leaked documents contradict that narrative: rather, detainees are targeted based on little more than their culture and religion – and are forced to undergo a draconian and often brutal brainwashing program. “The camps are terrifying, you’re monitored 24/7”, one woman said.

All four detainees spent months imprisoned in Xinjiang in 2017 and 2018. The interviews were conducted independently of each other, over the course of several weeks.

Since then, all four former detainees have escaped to Kazakhstan, and while DW is unable to independently verify their stories, their accounts corroborate each other in key aspects.

All four recalled the day they were handed a piece of paper detailing more than 70 acts and forced to choose one or several of them. Some of the acts were seemingly innocuous, such as traveling or contacting people abroad. But most of them were religious acts, such as praying or wearing a headscarf.

Another was handed the paper by a teacher through the bars in the camp's classroom that separated the teaching staff from the students guarded by armed officers sporting stun guns. "They threatened us: 'if you don't pick anything, that means you did not confess your crime. If you don't confess, you will stay here forever.' That's why we picked one crime," the female detainee who was imprisoned in March 2018 told DW.

All detainees DW spoke to agreed that the document they were pressured to sign was a numbered list of more than 70 alleged crimes.

It seems to be based on another list detailing 75 acts that the Chinese authorities consider to constitute "extreme religious acts," which was circulated in Xinjiang around 2014, most likely in order for residents to identify suspicious behavior and report it to the police. It includes such acts as "inciting jihad," "advocating sharia law," "forcing women to wear a headscarf" or "distributing religious propaganda material," but also more innocuous acts such as suddenly giving up smoking or drinking.

One of the female detainees told DW of the horror she felt when she was handed the list and was forced to pick a crime and sign the list. She could not sleep for days, she says — afraid she would never be able to return home.

Another said it almost came as a relief: "To be honest, we were happy — at least we now knew the time period we would spend in the camp. Before that, no one told us how long we had to stay." Detainees were also told that if they cooperated, the number of years they would be forced to spend in the camp might be reduced.

The fact that most acts deemed illegal were of a religious nature is a further indication that the Chinese authorities are targeting the religion and cultural practices of its Muslim minorities in an attempt to eradicate them, as activists have long claimed.

A few days after they were forced to pick a crime and sign the list, one detainee told DW, officials started calling people out one by one.

She was, she said, so terrified that she fainted and was taken back to her room. She was sentenced in absentia. "I was given 2 years for traveling abroad. I started feeling very sad, but still, compared to other people, my sentence was the lightest. Some people were given six years, 10 years even." The longer sentences, she says, were meted out for religious acts, such as praying or wearing a headscarf.

The detainees who received the lengthy prison terms, she says "started sobbing and crying. I felt really sorry for them."

But despite her shorter sentence, she says she lost all hope. "I thought: 'In two years, I will be dead.'"

The proceedings seemed to differ slightly from camp to camp: In one, prisoners' relatives were present and forced to sign the sentence.

In another, prisoners were sentenced individually, one at a time, and forced to sign the document detailing their sentence.

But all trials had one thing in common: There were no lawyers and no opportunity for detainees to defend themselves.

One detainee, a businessman who used to export vegetables from China to Kazakhstan, says he was terrified and couldn't sleep for days. He believes the authorities came up with the so-called trials "in order to find some excuse to show that I was a criminal".

All four former detainees were adamant they had not committed any crime. One man, his anger palpable in his voice, said he felt very angry every time he recalled his experience: "I never did anything wrong and still I ended up like this."

Soon after the trials, detainees started disappearing: Some were taken at night, shackled, blindfolded and marched away; others were called from the classroom, never to return.

But here, too, there was a pattern: Only those with lengthy prison terms, more than 10 years, disappeared — all of them prisoners, the four former inmates agree, who had confessed to religious acts, such as praying regularly or acting as an unofficial imam.

This is corroborated by researchers and activists who say imams and those deemed religious are more likely to be sent to prison, sometimes for decades, most likely as they are considered "irreformable."

Others were sent to labor camps, like one detainee who told DW she was forced to work in a glove factory. It was one of many factories that, through a government-sponsored scheme, researchers say have sprung up in villages across Xinjiang, some of which produce for foreign companies and supply chains.

Others are released into a draconian house arrest — their every movement monitored, their freedom of movement strictly curtailed.

"You are not allowed to move or travel freely, you cannot talk to other people, you cannot go to crowded places, you cannot visit your relatives," one former detainee told DW. "You can only stay at home and go to the village administration office," he said.

On several occasions, he and his wife were forced to publicly admit to their "crimes" in front of hundreds of people: He was forced, he says, to praise the Communist Party and thank it for the opportunity he was given to receive an education and change his ways — even though, he says, he did not learn a thing during his time in the camp.

Another detainee who was released into house arrest was forced to host various party members every week. She would be expected to cook for her overnight guests and treat them with respect. Living alone, having to host both men and women she was not related to, made her feel deeply uncomfortable, she says.

Every morning, she says, she had to attend a flag-raising ceremony, followed by seemingly endless political meetings and Chinese language classes. "It was exhausting," she says. "I was so tired all the time."

Eventually, all four detainees were allowed to leave China — most likely, because they had relatives in Kazakhstan who were campaigning on their behalf, and two held Kazakh citizenship or residency.

Their experience has left deep emotional and physical scars. All of the former inmates DW spoke to suffered from obvious post-traumatic stress disorder, including memory loss and insomnia. During the interviews, they alternated between rage and tears, as they recalled their ordeals, which included interrogations and sexual abuse. One woman told DW that every night, over the course of several months, she had been forced to pick up female detainees from a small room and accompany them to the showers.

While she was too scared to talk to the women, she said it was clear what they had been through: they had been raped by the guards. It is an allegation that Uighur activists have raised before.

Another woman told DW she had been beaten severely in the stomach during an interrogation and has been unable to get pregnant ever since. "My husband says I've changed, I'm a different person." Before, she used to love socializing and parties. "But now I've started hating people." She told DW of fits of seemingly unexplainable rage and chronic exhaustion.

A male detainee told DW of a similar feeling of emptiness: "I don't have any feelings towards my relatives or my children, I used to love my children very much, but now I don't feel anything anymore."

He had, he said after a pause, "lost all interest in living."