It happened on Sidwell Street, Exeter.
Officers are looking for witnesses after an 18-year-old woman was pulled to the floor by her hair in Sidwell Street between 12.10pm and 12.35pm on Thursday 6th June.
The attack has had a significant impact on the victim and several passers-by intervened and assisted her at the time.
Anyone who has information is urged to contact police by calling 101, or emailing firstname.lastname@example.org, quoting crime reference CR/050117/19.
Information can also be passed anonymously to independent charity Crimestoppers by calling 0800 555111, or via www.crimestoppers-uk.org