A 60-year-old woman died in hospital after being rear-ended by an alleged impaired driver on Highway 400 in Vaughan early Sunday morning.

OPP Sgt. Kerry Schmidt said the collision occurred in the southbound lanes of the highway, approaching the ramps to Highway 407, at about 2 a.m. Sunday.

Schmidt said one vehicle rear-ended the other, and four occupants of the vehicle that was struck from behind were injured requiring treatment in hospital.

York Region paramedics said three people were taken to a local hospital, and another, identified by police as a woman, was taken to a hospital trauma centre.

The woman was pronounced dead in hospital, Schmidt said.

The woman who was killed has been identified by police as Arti Vyas from Mississauga. 

Jonathan Ian Brown, 25, faces 11 charges including three counts of impaired driving causing bodily harm and dangerous operation of a motor vehicle causing death. 

A quantity of marijuana was also found in the car Brown was driving, Schmidt said.

The southbound lanes of Highway 400 were closed until about 8 a.m. Sunday to allow for cleanup and an investigation.