Police say a 10-year-old girl has died after being struck by a vehicle in Vaughan, Ont., over the weekend alongside her brother who also died.

York Regional Police say the girl and her four-year-old brother were injured Sunday afternoon when a car veered off the road and into their driveway.

A neighbour who was helping the children with a bike chain was also hurt.

Investigators say they are upgrading the charges against the driver, a 16-year-old boy from Richmond Hill, Ont., who was arrested at the scene.

The teen is now charged with two counts each of dangerous operation of a vehicle causing death and criminal negligence causing death.

He is also charged with one count each of dangerous operation of a vehicle causing bodily harm and criminal negligence causing bodily harm.