BBC:
The protests were over a plan to merge a Nanjing college in Jiangsu province with a vocational institute - which are seen as less prestigious.
AFP:
one video circulating on Twitter showed dozens of police and security personnel shoving and yelling at students in a crowded school hall.
Another showed thousands of chanting undergraduates surrounded by lines of officers on a sports ground, as police dragged some out of the crowd.
One student witness confirmed the authenticity of the images, estimating that around 3,000 students and 400 police officers were involved.
A thread featuring videos.