Police are appealing for information after a 12-year-old boy was pushed off his bike in Aylesbury.
The incident happened between 4.30pm and 5.50pm on Friday June 29 in Putman Street, off Bicester Road.
The victim was with two friends, one of whom was on a bike.
The group of boys were near to the Volkswagen dealership when a man asked the victim if he could borrow his bike.
After the victim refused, the offender climbed onto the bike, pushed the victim off backwards and rode off, in the direction of Whitehill Park.
The boy was not injured in the incident.
Police say the offender is white, aged between 25 and 35, around 6ft, of medium build and had curly hair and was wearing a white T-shirt and dark blue jeans.
The bike stolen was a silver and red 16in Carrera mountain bike.
Detective Constable Carolyn Bailey, based at Aylesbury police station, is investigating the crime.
Anyone who saw the incident or the offender, who was riding the bike in the Palmer Avenue / Whitehill Park direction is asked to contact police via the 101 number, quoting the reference 43180197765.