The two sex attacks in Brighton last week are believed to have been carried out by two different men.
Sussex Police said that detectives had initially believed that they were linked but no longer regarded this as the case.
The sexual assaults happened in the town centre in the early hours of Thursday (29 December) and Friday (30 December).
Detective Inspector Mick Jones said: “While the close proximity and timings of the two assaults made it appropriate for us to consider the possibility that they were linked, further inquiries and investigation have now shown distinct differences in the descriptions of the suspects.
“We are, therefore, now satisfied that the two incidents are not linked.
“Detectives continue to work diligently to try to identify the suspects in each case.”
On Thursday at about 1.45am an 18-year-old girl was sexually assaulted and punched in the face before she managed to escape.
The attack happened off Russell Square, Brighton.
On Friday at about 2.30am a 20-year-old woman was grabbed from behind by a man.
He pulled at her clothing and sexually assaulted her before she broke free and run away.
The attack happened in Steine Lane, an alleyway off Old Steine, behind the Pavilion Tavern.
Anyone with information about either attack is urged to called Sussex Police on 101 or the independent charity Crimestoppers anonymously on 0800 555111.
