The Education Bureau is investigating an incident of suspected teacher violence at a school in Tung Chung after a video of the incident was posted on the internet this week. The video appears to show a stocky middle-aged teacher at Wong Cho Bau Secondary School attacking one of his male students and pinning him to the floor in the classroom. The low-grade video - which looks to have been shot by another student in the class using a mobile phone - was posted on YouTube on Tuesday. By last night it had been viewed nearly 33,000 times. Deputy principal Chau Yu-fai said yesterday that the school had completed its investigation of the incident, which occurred between last September and early November. 'Contrary to what it looks like in the video, this was not a fight between the teacher and the student,' he said. 'The teacher was attempting to restrain a student who was emotionally unstable and had lost self-control, to prevent him from causing harm to other students.' However, he admitted that the teacher's actions were 'not entirely appropriate' and that the school had stepped up staff training on how to handle problem students peacefully. Mr Chau declined to name the teacher and said he had already left the school 'for personal reasons'. The 23-second clip cuts into the middle of the altercation at the school, which is sponsored by the Federation of Education Workers. At the beginning of the video, the student appears to have been knocked to the ground. When he gets back to his feet, the teacher rushes forward, grabs him roughly either by the shoulders or around the neck and forces the student back to the floor. The student advances on the teacher, swinging his arms in a threatening manner. After an editing cut, there is a verbal exchange in which the student can be heard accusing the teacher of hitting him. 'I didn't hit you,' the teacher responds. 'You want to hit me? Come on, then.' In a brief statement released last night, the bureau said education officials had visited the school yesterday morning as part of its investigation into the incident. 'This bureau will never tolerate violent behaviour occurring on school campuses,' it said. However, the bureau would not say whether it would track down the teacher or what action could be taken against him.