An Ashburton College student is in hospital after being badly beaten at school on Friday.
Police are investigating after two year nine students got into a fight.
The victim's mother told The New Zealand Herald her son was badly beaten and suffered a fractured eye socket, a minor neck injury and a concussion.
The College's principal Simon Coleman confirmed the "completely unacceptable" assault took place during school time.
It took time for a teacher to arrive because the fight happened in a small space off the main classroom, he said.
"The boy responsible was sent home and we are following our school discipline process in responding to this incident," he said.
"This behaviour is completely unacceptable and goes against everything the school stands for."
Coleman "fully supported" the victim's family reporting the assault to police.
Staff were supporting the victim and his family by arranging hospital visits, providing taxi vouchers and contributing to medical costs, he said.
The school also reported the assault to the Ministry of Education on Monday, when accounts from witnesses had been taken.
Ashburton College was following its internal processes but the Ministry would provide support if it was needed, the Ministry's Hautū Te Tai Runga south leader Nancy Bell said.
Late last year, two violent fights were filmed at Ashburton College, following a 2022 review into bullying claims at the school.
The review was commissioned following media reports of alleged bullying incidents over an eight-year period.