Highway 401 eastbound express lanes are now open after being closed for most of the day as a result of a multi-vehicle collision. 

The express lanes were blocked at Weston Road after several vehicles collided on Monday morning.

Toronto police reported that four vehicles were involved in the crash, describing it as "very serious."  

Multiple ambulances were called to the scene, and Toronto paramedics said they had taken two patients to a trauma centre with life-threatening injuries.