A pedestrian is dead after being struck by a vehicle on Highway 403 in Mississauga on Tuesday night, Ontario Provincial Police say.

The collision happened in the highway's eastbound lanes at Hurontario Street. Police were called to the scene at about 7:20 p.m. The driver remained at the scene.

Sgt. Kerry Schmidt, spokesperson for the OPP's Highway Safety Division, said the person was pronounced dead at the scene.

Schmidt said police do not know why the person was on the highway.

All Highway 403 eastbound lanes and on ramps at Mavis Road remain closed. Motorists are urged to avoid the area as the OPP's collision reconstruction team continues to investigate.