Five lorries were shot at in Felixstowe, Suffolk. It happened between 9.30pm on January 22 and 2.30am the following morning.
Police believe an air weapon was used to target the heavy goods vehicles. None of the drivers were injured but all their cabs were damaged.
The were following a diversion from the A14 Eastbound along Walton High Street. Police have asked any witnesses to call 101 quoting reference 4208/18.