The teenager was injured and his mobile phone was damaged during the assault which happened at around 4.40pm on Friday near to the junction of Westway and High Street in the Eastfield area.
The suspect is described as a white boy aged around 15 with brown hair. He was wearing a black hooded top with grey tracksuit bottoms. At the time he was in the company of a second youth who was also white, about 15 years old with blond hair. He was wearing a white hooded top with grey tracksuit bottoms.
Anyone with information that could assist the investigation should contact North Yorkshire Police on 101, select option 2, and ask for David Williamson or email [email protected]
To remain anonymous pass information to Crimestoppers on 0800 555 111 and use the North Yorkshire Police reference number 12180195823.