The owner of a shop nearby said the gangsters had showed up demanding knives, but the shopkeeper refused and managed to record the incident.
The clip shows some 20 people dressed in the uniforms of two rivalling vocational institutes showing up with arms and charging at each other.
Police said the clip will be used as evidence to track down the offenders, adding they should all be arrested soon.
Locals have told police to visit the area more often as they are afraid a similar incident may take place and they could be harmed by the gangs.