A parents' organisation in Northern Ireland has called on schools to help to stop the increasing number of incidents in which teenagers film videos of fights and post them on the internet.
Pip Jaffa, chief executive of the Parents Advice Centre, said the practice was a form of bullying: "The fights appear to be orchestrated and it's very worrying that young people feel that it's acceptable," she said.
Police have launched an investigation into the attacks. Some of the pupils are named on the websites and the schools can be identified through their uniforms.
Inspector Roy Robinson told the Belfast Telegraph that he would be contacting schools to try to identify all the pupils involved and called for anyone with information to call the police.
One of the videos is understood to show two teenage boys being forced to fight while 30 of their peers look on; it has been viewed nearly 4,000 times.
"Anybody who is portrayed in a distasteful way can feel a sense of humiliation and embarrassment, particularly teenagers, who are at an age where they are more self-conscious," said Ms Jaffa. MR.