Inspector Matt Srhoj, area commander for Counties Manukau police, thanked the community for helping with the investigation.
"This assistance clearly demonstrates that the wider community has, like police, zero tolerance for this sort of violent behaviour," he said.
"The public will have noticed an increase in police presence around the Māngere East and Ōtāhuhu areas over the past week.
"Our presence has been for reassurance and for prevention of any further disorder."
Srhoj said the police presence would continue "for the time being".
Community leaders had called for calm after Friday's stabbing.
Māngere MP Aupito William Sio said he had offered support to De La Salle College's principal and Board of Trustees in the wake of the brawl.
"I am really pleased with the confidence they have shared with me that De La Salle College, like all schools, is a safe learning experience for all their students, and our parents and the wider Māngere community should have every confidence that when their children arrive at school, that it is a safe environment," Sio said yesterday.
Video obtained by the Herald shows students fighting and yelling in the street.
One De La Salle student was stabbed in the stomach, while another suffered concussion in the fight.
