Two would-be robbers got off a moped to punch a teenager in the face in Cotmanhay, police have said.
The riders sped past as the 18-year-old was walking along Wesley Street at about 11.55pm on Thursday (August 8).
They stopped at the junction with Mount Pleasant, got off the bike and headed towards him.
The passenger demanded the teen hand over cash and his mobile phone but when he refused the passenger hit him in the face.
Both men got back on the moped and rode off.
The driver was described as white, aged about 20, slim and around 6ft tall.
He wore a black helmet, black and grey jacket and black bottoms.
His passenger was also white and of the same age and height as his friend.
He was stocky and wore a grey helmet, grey jacket and dark trousers.
He spoke with a local accent.
The moped had an L plate.
Anyone with information should call police on 101.
Alternatively call anonymously on Crimestoppers on 0800 555 111.