Seven cars were vandalised in one night in two streets in Chickenley.
Red paint was sprayed onto parked cars in Princess Crescent and Princess Road, overnight between June 17 and June 18.
It is believed that those responsible then walked towards Chickenley Lane and threw away the canister.
Police are examining CCTV footage to try to identify the culprits.
Any witnesses or anyone with information is asked to contact their local NPT on the non-emergency number 101 or Crimestoppers in confidence on 0800 555 111.