Detectives at Strand Road are investigating a serious assault that occurred in the Clooney Road area of Derry sometime around 5.30pm on Saturday 8th August.
Detective Constable Richard Donnell is keen to speak to anyone who was in the area at that and who may have witnessed the incident during which a male was knocked out.
The man, aged 19, sustained injuries to his face and jaw.
Police are also keen to trace the driver of a cream MINI whose car may have been damaged in the process.
Information can be given on the police non-emergency number, 101 or by calling the Crimestoppers Charity anonymously on 0800 555 111.