A teenager was repeatedly punched after three men stole his bike last week.
The 17-year-old victim was cycling near Railway Bridge in Buckingham Road, Bletchley, when he was called over by a group of three men at around 3.30-3.50pm.
One of the men asked to borrow his bike. Initially, the victim said no, but eventually agreed.
The offender then cycled away on the bike and the other two men followed.
The victim also followed and tried to take the bike back, but one of the men punched him several times. They then headed off to Water Eaton Road with the bike.
One of the offenders was Asian, 5ft 8ins, in his late teens, with short dark brown hair. He was wearing a red Ralph Lauren cap and black Adidas tracksuit bottoms.
The second offender was black, in his late teens, 6ft 2ins, with short black hair shaved around the sides and an afro style on top. He was wearing a black puffy jacket.
The third offender was black, 5ft 11ins, with short black curly hair. He was wearing a grey hoody.
The stolen bicycle was a white Scott Aspect 45 mountain bike with blue lines and the word Scott in black.
Anyone with information is asked to call Thames Valley Police on 101.
Alternatively call Crimestoppers on 0800 555111.