Two teenage boys are believed to have filmed their friend sexually assaulting a high school peer using their mobile phones in Kavala, northern Greece, and passed the footage around to their schoolmates, authorities said yesterday.

Police said the incident took place last week when a group of five to six high school students gathered at a home belonging to one of their relatives to listen to music.

For a reason which has yet to be determined, one of the boys sexually harassed his peer in front of the other students, while two others filmed the incident.

According to one press report, the attack was intended to punish the victim for knocking over a motorcycle belonging to the alleged offender.

A prosecutor has ordered a preliminary investigation into the incident and called the students involved in for questioning.

Education Ministry officials said the incident is not related to sit-in protest action taking place at schools in the area.