OSHAWA, Ont. -- A five-year-old boy has been seriously injured after being struck by a van in Oshawa.

Durham regional police say the incident happened just before 3 p.m. Wednesday in the city east of Toronto, as the boy crossed the road with a 12-year-old girl.

It's alleged a van driven by a 54-year-old Oshawa man struck the boy just after it entered the intersection (Harmony Road North and Rossland Road East).

Police say witnesses reported seeing two children running across the road at a crosswalk as the traffic light turned red and that the light for the vehicle was green at the time of the collision.

The five-year-old boy was airlifted to Toronto's Hospital for Sick Children with serious injuries.

Police say the driver and passenger of the van were not injured and remained on the scene to help the child.

An investigation into the incident is continuing and police are asking anyone with information to contact the traffic services branch of Durham Regional Police.