New Delhi, Oct 5 (IANS): Hundreds of police officers armed with rifles went house to house in Uyghur communities in China's Xinjiang region, pulling people from their homes, handcuffing and hooding them, and threatening to shoot them if they resisted, CNN reported.

"We took (them) all forcibly overnight," a former Chinese police detective told CNN. "If there were hundreds of people in one county in this area, then you had to arrest these hundreds of people."

The former detective turned whistleblower asked to be identified only as Jiang, to protect his family members who remain in China.

In a three-hour interview with CNN, conducted in Europe where he is now in exile, Jiang revealed rare details on what he described as a systematic campaign of torture against ethnic Uyghurs in the region's detention camp system, claims China has denied for years.

"Kick them, beat them (until they're) bruised and swollen," Jiang said, recalling how he and his colleagues used to interrogate detainees in police detention centres. "Until they kneel on the floor crying."

During his time in Xinjiang, Jiang said every new detainee was beaten during the interrogation process, including men, women and children as young as 14.

The methods included shackling people to a metal or wooden "tiger chair" -- chairs designed to immobilise suspects -- hanging people from the ceiling, sexual violence, electrocutions, and waterboarding, according to the former detective.

Inmates were often forced to stay awake for days, and denied food and water, CNN quoted Jiang as saying.

"Everyone uses different methods. Some even use a wrecking bar, or iron chains with locks," Jiang said. "Police would step on the suspect's face and tell him to confess."

The suspects were accused of terror offenses, said Jiang, but he believes that "none" of the hundreds of prisoners he was involved in arresting had committed a crime.

"They are ordinary people," he said.

CNN cannot independently confirm Jiang's claims, but multiple details of his recollections echo the experiences of two Uyghur victims it interviewed for this report.

More than 50 former inmates of the camp system also provided testimony to Amnesty International for a 160-page report released in June, titled "'Like We Were Enemies in a War': China's Mass Internment, Torture, and Persecution of Muslims in Xinjiang".

The US State Department estimates that up to 2 million Uyghurs and other ethnic minorities have been detained in internment camps in Xinjiang since 2017.

China says the camps are vocational, aimed at combating terrorism and separatism, and has repeatedly denied accusations of human rights abuses in the region, the report said.

Jiang said even before his time in Xinjiang, he had become "disappointed" with the Chinese Communist Party due to increasing levels of corruption.

"They were pretending to serve the people, but they were a bunch of people who wanted to achieve a dictatorship," he said.

In fleeing China and exposing his experience there, he said he wanted to "stand on the side of the people".