THREE vehicles were struck by rocks at Muswellbrook in an incident that has sparked a police investigation.
Hunter Valley Police District investigators are seeking public help after rocks were thrown from the railway overpass above Bridge Street about 11.30pm on Tuesday night.
Police said the stones hit three vehicles as they headed south.
Extensive patrols were conducted but officers were unable to find the person or people responsible.
Anyone who witnessed the incidents or saw people in the area at the time is urged to call Crime Stoppers on 1800 333 000 or Muswellbrook police on 6542 6999.