Three vehicles, including a TTC bus, were involved in a collision on Sunday morning.
Toronto police were called to the area of Weston Road and Knob Hill Road in North York just before 11 a.m.
Officers say emergency crews are on scene, but it is currently unknown if there are any injuries.
Toronto Fire Services is also on the scene.
Authorities are warning residents in the area to expect traffic delays and to consider alternate routes.
