Investigators have been told a woman in her 30s was talking on her mobile phone while walking along Russell Street when the device was snatched from her about 3pm on 17 July.
The victim chased two female offenders and managed to retrieve her phone but was assaulted in the process.
The first female is perceived to be Caucasian in appearance, aged in her late teens to early 20s, approximately 165cm tall with bleached blonde hair.
The second female was also of Caucasian appearance, late teens to early 20s, and about 170cm tall with dark hair.
Investigators have released images of two females they believe may be able to assist with their enquiries.