Video has emerged of the brutal brawl which broke out near a south Auckland KFC on Monday evening.
The fight, which began as a one-on-one confrontation, quickly escalated to more than 80 teenagers.
The video shows students fighting each other outside the Mangere East Hall before spilling on to Massey Rd towards the KFC. Several people are pushed to the ground and one person appears to be knocked out in a single punch.
Police are now saying around 80 people were involved - not the 100 previously estimated - and they used knives, plywood and chairs as weapons.
Police were called to "reports of public disorder" outside the Mangere East KFC on Massey Rd just before 5pm.
Four people were arrested at the scene, including two 17-year-olds on a range of charges including disorderly behaviour and one of possessing a knife. Two 15-year-olds were referred to Youth Aid.
Another 15-year-old has since been referred to youth aid and police say more arrests are likely.
Counties Manukau West area commander Jason Hewett says police want to make sure this doesn't happen again.
"We absolutely understand how terrifying this fight must have been for those members of the community caught up in it, it obviously terrified a number of people and I would like to reassure the community of Mangere that we are all over this."
He has labelled the behaviour "utterly appalling" and says "it's by the grace of God that no one was seriously injured as a result".
Police have increased patrols in the area to prevent further violence.
"We are working very closely with those we've already identified, with their parents, with the schools concerned to make sure that there is no further retaliation or fights going forward."
The police investigation is in an infant stage and area commander Hewett says footage of the fight is "coming in slowly".
Anyone who filmed the fight is asked to contact Detective Sergeant Steve Nightingale on (09) 261 1300.
Newshub.
