The shocking assault took place at Wauld’s Bank Drive on Friday, November 25 at around 8.30pm.
While walking in the dark, the teenager was approached by the masked gang, who attacked her.
The thugs tried to steal her phone and knocked her to the ground.
Con Kirsty Forth said: “This was a nasty and unprovoked attack on an unsuspecting victim.
“We won’t tolerate this kind of behaviour in our county. This incident is treated very seriously by the police and we are following a number of lines of enquiry to establish what happened. Anyone who saw the group in the area or noticed anything suspicious is asked to contact us.”
Anyone with information is asked to contact police on 101 or call Crimestoppers, anonymously, on 0800 555 111.