Liverpool Leader reported this morning that a teenage girl was allegedly approached by a group of six men in the forecourt of the Liverpool Library on George St about 9:20pm on Saturday.
According to police the girl spoke briefly with the group before she was invited to meet a mutual friend.
She was then lured to a car park stairwell and was sexually assaulted by two men while the others looked on.
The teenager walked back to the library where she was helped and police were called.
An investigation has already started and detectives are appealing for anyone who may have information about the incident or anyone involved to come forward.
All six males have been described as being of African appearance and aged about 20.
Liverpool police they had nothing further to add at this stage and investigations are continuing.
Call Crime Stoppers on 1800 333 000