Some students were peacefully sitting near Admiralty early on Dec. 1 when a plainclothes policeman picked on one of the girls, NTD Television reported.
The man became angry, and told the girl he would take her back to the police station to rape her. She questioned his intentions, and they started arguing.
Then two more plainclothes police came over and they surrounded her. The girl panicked and tried to run away, but fell down some stairs.
A group of young students came over to help her, and asked the policemen how they could dare to do this. The first officer took out his baton while one of the others fell to the ground as if he had fainted.
Things became chaotic when more people arrived, and the man with the baton used this as an excuse to chase after the students and hit whoever he could reach.
A former policeman witnessed the scene, and described what he had seen during a radio interview. Apparently one of the students tried to check the ID of the man on the ground, so he stood up to get it back, and then fell to the ground again. A group of protesters formed a circle around him to stop things getting out of hand.
By this time a large number of police were there, and organized an ambulance to take the man away.
Many people believe he faked having passed out to make the protesters look bad.
A police spokesman said on Dec. 2 that the matter is being investigated.