A video that has emerged of a fight between a group of Ashburton College students targeting one teen has left a mother fearing for her child's safety.
The video, which was sent to the Herald by a concerned parent, shows two college students throwing punches at each other while others stand around and watch.
As the video continues, countless other students become involved in the fight, launching in and punching a student on the ground.
The footage continues for about 16 seconds before anyone steps in to stop the attack.
A concerned mother, who wished to remain anonymous, said this was one of many incidents she knew of at the school. She believed violence had increased dramatically over the past two years.
"The incident occurred after a boy confronted a gang member after his bike had been stolen.
"What started as a one-on-one fight over the stolen bike, turned into a savage beating of an innocent pupil," she said.
"Teachers are unable to prevent these gangs intimidating other pupils, my child and friends are no longer able to visit the school canteen on their own.
"They make sure they are always in twos or threes as they move around the school," she said.
The mother believed it was time the school employed security guards to patrol the grounds during the day.
"The teachers are unable to stop this behavior. The school must consider contracting security guards to protect our children or one day you will be reporting on a murder at this college.
"It only takes one coward to punch some body in the back of the head to kill them," she said.
Ashburton College principal Ross Preece confirmed he was aware of the incident and the video.
"Yes students are being disciplined over this. There are three suspension meetings scheduled," he said.
Preece said any violence at the college seemed to be at Year 9 and 10 level.
"Our students don't like violence and if you look closely you will see a couple of lads trying to drag a mate out of the scrap, because they are aware that such incidents are treated very seriously by our board of trustees.
"Aside from the traditional stand down and suspensions we are involved in a number of programmes including 'culturally responsive and relational pedagogy' - really about the relationships between learners and teachers.
"Plus 'Positive Behaviour for Learning' and restorative practice. Both of these last two have been the major focus this year.
"We also have 24/7 youth workers to support our students."
Preece said the school was not considering employing security guards.
"There is no gang problem at our school. We have a handful of students from families with gang backgrounds, out of 1200 students, and they respect our school as a place that they can get on with their learning.
"None of the lads involved are gang members or are from gang households. The fight had happened over a stolen bike."
Ministry of Education deputy secretary Katrina Casey said it had not received complaints about the incident at Ashburton College.
"We have spoken to the principal and are satisfied that the school is taking this matter seriously and has appropriate systems in place to effectively manage this situation.
"We understand how distressing an incident like this can be, not only on those directly impacted, but for all students and staff, and they are aware we are available to provide support if needed," she said.
Casey said all students deserved to feel safe at school.
"We take incidents of violence very seriously and most schools have clear policies and procedures in place to manage this type of unacceptable behaviour.
"The boards of trustees are responsible for behaviour management and disciplinary processes, and make all the decisions themselves on the outcome of any incidents."
The school's board of trustees has also been approached for comment.
The school also made news headlines in March last year after a female student was knocked unconscious in a vicious assault that was filmed and uploaded to social media.
Kaylee Evans, 14, suffered a concussion and was left with chipped teeth after being stomped in the head.
At the time her mother called for greater security in schools.