Avon and Somerset Police say they are seeking witnesses after a number of cars were damaged in the Patchway area.
The incidents happened on Monday lunchtime (20th May) between midday and 12.45pm in Rodway Road.
Police believe that a man, who was dressed in a black top and black trousers, damaged the vehicles, which were parked outside a row of shops including Jhoots pharmacy and the Cyclops store.
It is believed there may have been people in the area at the time of the incident who may have information to assist with enquiries. Anyone able to help is asked to contact the police on 101 or via the online crime reporting form.
Alternatively contact the independent charity Crimestoppers on 0800 555 111. They never ask your name or trace your call.