A woman was assaulted in Upper Mounts during the early hours of Easter Sunday.
The 31-year-old woman was near the former Chronicle and Echo site when the assault took place sometime between 4.30am and 5.30am on Sunday.
The offender was a tall man of large build.
Police would like to speak to anyone who may have witnessed this incident or have any information regarding it.
Witnesses or anyone with information about this incident is asked to call police on 101 or independent charity Crimestoppers anonymously on 0800 555 111.