Police say they received a report of a group of boys who were believed to be in possession of weapons, including a firearm and a knife, at Campbell Collegiate on Friday evening.
Officers arrested two 15-year-olds and two 14-year-old boys at the school during a provincial wrestling championship event, according to police.
Police say the teens, who do not attend Campbell Collegiate, were carrying a pellet gun and two hunting knives.
There were no altercations or injuries reported during the arrests, police say.
According to police, one of the 14-year-olds was released without being charged.