Police said the startling incident began when a high school student contacted them and reported four classmates had approached his home armed and tried to start a fight.

The group then left in the direction of Robert Bateman Secondary School.

The police response was swift and thorough, with 30 officers – including Emergency Response Team members – locking nearby elementary and secondary schools.

“We’re talking lunchtime and students trying to start a fight with a firearm. We can’t take any chances,” Const. Ian MacDonald said.

“We believed there was a real threat and that that threat came in the form of a handgun or firearm.”

The largest police presence was at Robert Bateman Secondary, where students were forced to stay in class and anxious parents forced to wait outside as officers went room-to-room looking for suspects.

“The police were surrounding the school. It was not a good feeling,” parent Rob Roddick told CTV News.

Police said the other schools were locked down as a precaution, and only for a brief time.

The lockdown at Robert Bateman lasted three hours. It was lifted after police managed to find and arrest four suspects, none of whom can be identified because of their age, inside.

MacDonald said the teenagers are facing charges related to weapon possession and uttering threats.

“The incident they were involved in was a very serious crime,” MacDonald said.

On Friday, officials assured students and parents it was back to business as usual at the school, though some teenagers told CTV News several of their classmates absent.

With a report from CTV Vancouver’s Sarah MacDonald