A person in the fleeing car is in a critical condition, and another is in a serious condition.
A person in the car that was hit has also sustained critical injuries, while another person in that vehicle has minor injuries.
The Serious Crash Unit has examined the scene and the road remains closed. Motorists are being told to avoid the area unless they are residents.
The incident has been referred to the Independent Police Conduct Authority - a routine practice.
Police are seeking witnesses to the crash and any CCTV footage from the area at the time.
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