Warning: This report contains details of physical and sexual abuse and discussion of suicide.

Baobao's heart still races when she smells soil after morning rain.

It takes her back to early military drills behind locked gates - and the constant fear that marked every one of her days at Lizheng Quality Education School.

For six months, aged 14, she barely left the red and white building in a remote Chinese village where instructors tried to "fix" young people whose families considered them rebellious or problematic.

Students who failed to comply were beaten so severely they could not sleep on their backs or sit down for days, she says.