VANCOUVER -- An investigation is underway in Chilliwack, B.C., after a video surfaced online showing what appears to be a violent attack.

It is alleged that the incident happened Tuesday afternoon.

The video appears to show one teenager running up behind another, and pulling them from behind by the hair.

It looks like the person then throws the teen to the ground.

Chuck Lawson, principal at GW Graham Secondary, says the school is "actively working through" the incident. He says the school is taking it very seriously.

The Chilliwack RCMP also confirmed it is investigating.