A policeman was injured when his patrol car was in collision with a vehicle that failed to stop.
West Midlands Police said officers tried to stop a Range Rover Discovery which was being driven “erratically” in Wood End Road, Erdington, at 04:10 BST.
It collided with a passing patrol car, which was not involved in the pursuit, injuring the officer inside.
A man, 37, was arrested on suspicion of dangerous driving and driving whilst unfit through drink or drugs.
Police said the unnamed officer suffered pelvic, leg and shoulder injuries and remained in a serious but stable condition in hospital.
Residents said they were “shocked” at the crash.
Ch Insp Tony Cole, the force incident manager, said: “An investigation is under way to establish the circumstances of what took place this morning and I would urge anyone who witnessed the collision to get in touch.
“Support is being pro-actively offered to those who attended the scene and colleagues of the officer.”
The force’s Professional Standards Department has been informed, police added.
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