A driver was taken to hospital after his car was involved in a head-on collision with another car being followed by police in Middlesbrough.
Cleveland Police said officers were on a routine patrol when a Vauxhall Astra with three passengers failed to stop in Kensington Road on Friday night.
It was pursued by a police car with lights and sirens and collided with a taxi and a Citroen Saxo in The Avenue.
Four people who were arrested at or near the scene were released on bail.
The Saxo driver was taken to James Cook University Hospital with a fractured pelvis and leg.