A police car was rammed during a police pursuit through Burgess Hill on Tuesday which ended with four people being arrested.
Police say that officers were carrying out a routine patrol in an unmarked car in York Road, Burgess Hill, at around 2.10pm on Tuesday when the trouble started.
The officers spotted two BMWs, one of which was believed to have been reported stolen on May 9.
The officers followed the cars before one of them rammed the police vehicle.
More police cars and the police helicopter joined the resulting pursuit until one of the BMWs was stopped in Marchants Way, the other in Fairbridge Way - where a man ran off on foot.
A 21-year-old man from Burgess Hill was arrested on suspicion of conspiring to steal a motor vehicle and burglary but was later released without charge.
A 17-year-old boy from Burgess Hill arrested on suspicion of conspiring to steal a motor vehicle has been bailed until 3 June pending further enquiries.
A 17-year-old boy from Hertfordshire arrested on suspicion of conspiring to steal a motor vehicle has been bailed until 2 June pending further enquiries, say police.
Meanwhile, a 30-year-old man from Middlesbrough, arrested on suspicion of conspiring to steal a motor vehicle, has been bailed until July 5 pending further enquiries.
Police say they are searching for the man who made off on foot from the car stopped in Fairbridge Way.
Witnesses or anyone with further information are asked to email firstname.lastname@example.org or call 101 quoting reference 863 of 10/05.
Alternatively they can contact the independent charity Crimestoppers anonymously on 0800 555 111 (www.crimestoppers-uk.org).