Thames Valley Police is appealing for witnesses after a robbery in Milton Keynes town centre on Sunday.
At around 5.35am, a 22-year-old man was using his BlackBerry phone in the car park at John Lewis when he was approached by a man who threatened to stab him unless he handed over his phone. The victim handed over his phone and the offender followed him for a while shouting at him before leaving the scene. The victim received no injuries.
The offender is black, between 20 and 30-years-old, 5ft to 5ft 7ins, of medium build with short black hair and a goatee beard. He was wearing a white polo shirt, dark trousers and dark shoes.
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 DC Wendy Cissell of 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. No personal details are taken, information is not traced or recorded and you will not go to court.