An E-fit has been produced of a man wanted over a robbery at Meadowhall Rail Interchange.
A 16-year-old girl was threatened by a man who then grabbed her mobile phone on Bonfire Night.
The robber left via Tyler Street, turning left towards Roman Ridge Road, Wincobank.
A South Yorkshire Police spokesman said: “The man is alleged to have made verbal threats before taking her mobile phone.
“The teenager was not hurt but left shaken by the incident.”
Call police on 101.