Chinese Christians Held in Secretive Brainwashing Camps: Sources

From RFA.org (April 1):

Authorities in China are detaining Christians in secretive, mobile "transformation" facilities to make them renounce their faith, RFA has
learned.

A member of a Christian "house church" in the southwestern province of Sichuan who asked to be identified by a pseudonym Li Yuese said he was held in a facility run by the ruling Chinese Communist Party (CCP)'s United Front Work Department, working in tandem with the state security police, for 10 months after a raid on his church in 2018.

"It was a mobile facility, that could just set up in some basement somewhere," Li said. "It was staffed by people from several different government departments."

"It had its own (CCP) political and legal affairs committee working group, and they mainly target Christians who are members of house churches," he said.

The Chinese Communist Party, which embraces atheism, exercises tight controls over any form of religious practice among its citizens.

State security police and religious affairs bureau officials frequently raid unofficial "house churches" that aren't members of the CCP-backed Three-Self Patriotic Association, although member churches have also been targeted at times.

The CCP under Xi Jinping regards Christianity as a dangerous foreign import, with party documents warning against the "infiltration of Western hostile forces" in the form of religion. [read more]

Another article on the subject:

You Won’t Believe What the Chinese Communist Party is Teaching About Jesus