A man needed hospital treatment after he was attacked in a town street.
The 40-year-old man was near a bus stop on Glasgow Road near its junction with Castlegreen Street in Dumbarton when he was involved in an altercation with a man in a red car at around 6.45pm on June 2.
He was assaulted by the man, who then drove off down Castlegreen Street in his vehicle.
The victim went to the Royal Alexandra Hospital in Paisley where he was treated for a facial injury.
The suspect is described as 17 to 18 years old and was wearing a blue Rangers top, black shorts and was carrying a black rucksack.
He was around 5ft 6in to 5ft 8in, of average build with short dark hair.
Police are appealing for information about the incident.
Detective Constable Mark Gillies, from Clydebank CID, said: “I am appealing for anyone who may have witnessed this incident to please come forward.
“In particular I would like to speak to any motorists who were on Glasgow Road at the time, and may have dashcam footage which could be of significance.
“Anyone with information is asked to contact Clydebank CID through 101, quoting incident number 3078 of Wednesday, 2 June.
“Alternatively you can call Crimestoppers anonymously on 0800 555 111.”