A man had a knife waved in his face by a robber who followed him from an underpass to steal his phone.
As the victim walked through the Silbury Boulevard underpass he was asked for a cigarette lighter by a stranger.
As he continued walking towards Adelphi Street he was followed and made to hand over his green iPhone 5c.
The offender then brought out a small knife and began waving it in the victim’s face.
Thames Valley Police is appealing for witnesses to the robbery, which happened at 9.15pm on May 5, when the victim was walking towards Campbell Park along the Redway.
The offender is described as between 16 and 24 years old, about 5ft 10ins tall, skinny to medium build.
He was wearing a plain black body warmer with a red jumper underneath. He had a thin beard from ear to ear and a thin moustache which was closely cropped to his face.
Anyone with information should contact PC Graeme Poulton from Milton Keynes police station on the non-emergency number 101.