TORONTO -- Ontario's police watchdog is investigating a crash that sent a police officer and the driver of a diplomatic vehicle to hospital with injuries.

The Special Investigations Unit says the incident took place late Thursday afternoon in the city's west end when police tried to stop a vehicle.

The driver fled the scene, but crashed into two vehicles including one with diplomatic plates several blocks away.

The SIU says the driver of the diplomatic vehicle was taken to hospital with a serious upper body injury, while a police officer was also hospitalized with an undisclosed injury.

No details about the diplomatic car or its occupants were released.

The SIU is an arms-length agency that investigates incidents involving police in which someone is killed, injured or accused of sexual assault.