Chinese teenagers dressed in camouflage uniforms express gratitude in front of cameras at a youth correction centre, but the off-camera reality tells a completely different story.

According to a Chinese state media report they are beaten or sexually assaulted, leading to calls for better supervision and monitoring of such institutions.

Such schools accept teenagers who are rebellious, weary of studying, addicted to playing electronic games, or suffer from depression.

The institutions generally charge between 8,000 and 20,000 yuan (US$1,200 and US$3,000) a month to correct the behaviour of students in a quasi-military style, according to the news magazine Ban Yue Tan, a mouthpiece of the Communist Party.

Some camps use physical punishment disguised as “gratitude education” or “military education”, the report said.