A fight at Gisborne Boys' High School filmed on a cell phone and uploaded to Youtube has prompted the school to take disciplinary action against several students.
But the school said it would not report the incident to police.
The 10 second video, which was posted on Youtube yesterday, showed a male student punching another male student twice while holding him by the scruff of the neck.
The school's principal Greg Mackle became aware of the video when contacted by Radio New Zealand this morning.
He said the Year 9 student who threw the punches would face disciplinary action, as-well-as the students who filmed the incident.
"I'll be talking to the parents of the boys involved in the social media thing, pointing out the fact that they have done a very serious thing here and made some wrong choices about using social media," he said.
Mr Mackle said video had been removed.
He said the fight was caused by a misunderstanding.
"A plastic bottle was thrown by one boy into the air, it was not aimed at any other boy," he said.
"The bottle missed a boy by about 1-2m. This boy reacted unacceptably in then hitting the boy who threw the bottle."
He said the fight was an isolated incident and not indicative of the school's culture.