One of two muggers punched a teenager in the face in Huddersfield.
The 15-year-old suffered bruising when he was hit by one of two youths who accosted him in Leeds Road, Bradley.
He was forced to hand over a mobile phone and a gold chain.
Both thugs were aged 18 or 19 and about 6ft tall. One was black and wore a black hooded top with built-in goggles.
The second was of mixed race with a round face. He wore a red and black cap with a large, flat peak. The theft happened about 11.15pm on Tuesday night.