Thames Valley Police is appealing for witnesses after a robbery in Milton Keynes on Thursday.
At around 1pm, a 17-year-old boy was walking from the city centre to the Xscape building along the underpass at Seclow Gate.
He was then approached by a man on a bike who punched him in the stomach and took the £10 that the victim had in his hand. The offender cycled off in the direction of Central Milton Keynes.
The offender is black, 20-years-old, tall and of slim build. He was wearing a black Carbrini jacket with white writing.
The bike was a BMX style.
Police would like to speak to anyone who witnessed the offence, recognises the description of the offender, or who saw the offender in the area around the time of the incident.
Anyone with any information should contact Det Con Wendy Cissell at the Priority Crime Team based in Milton Keynes via the 24-hour Thames Valley Police Enquiry Line on 101.
If you don’t want to speak directly to the police you can contact the independent charity Crimestoppers anonymously on 0800 555 111 or online at crimestoppers-uk.org.