Ontario Provincial Police says emergency crews are at the scene of a serious collision on Highway 401.
OPP representative Rob Knight said at around 2 p.m. officers were called to a four- or five-car collision eastbound on Highway 401 just before Leslie Street.
Toronto paramedics told Global News that three people were taken to a trauma centre with serious injuries.
Toronto fire said two people were trapped in vehicles when they arrived on scene. Fire said they have since been extracted and are conscious and breathing.
OPP said all but one eastbound lanes are closed, and drivers should expect heavy delays on the collectors.
In footage captured by Global News, motorists were seen doing U-turns at the collector lanes to avoid traffic delays.
More to come.