A string of attacks on women in Brighton may have been carried out by the same man, police believe.
Sussex Police are investigating two separate attacks on women in Union Road, next to The Level, which took place shortly before 8pm on Thursday.
And they are looking into possible links to crimes in Hollingdean, the Vogue Gyratory and The Level in November and Dcember.
On Thursday night, a man ran past two women and reportedly sexually assaulted both of them over their clothing.
Police have only been able to trace one of the women, a 20-year-old who was described as "very shaken" but unhurt.
Detective Sergeant Mark Cullimore said: "We are appealing for witnesses about the assaults and would very much like the second woman to contact us so that we can be assured that she is safe and well, and give us account of what happened."
The man was Arabic or Asian-looking, light-skinned, about 5ft 9in, in his mid to late 20s, and of medium build.
On December 8 a 21-year-old student was indecently assaulted while walking into Hollingdean Road from the Vogue Gyratory, after getting off a bus at Sainsbury's.
At 7.35am on Sunday, November 18, a 26-year-old woman jogger was indecently touched. She shouted at the man, who walked away.
Police believe minutes earlier the same man had unsuccessfully tried to steal from a woman on the path on the Lewes Road side of The Level.
Detective Sergeant Cullimore said: "It is not clear what the real motive was in these incidents and we have not yet established a definite connection between those last night and the previous ones.
"In each case the suspect did not speak to or threaten the women and just made off.
"We need to find whoever is responsible as quickly as possible and we hope that people may have seen what happened or recognise the description."
He said extra police patrols are being made in the areas where crimes have been reported.
Anyone with information is asked to call Sussex Police on 101, quoting Operation Ampfield, or Crimestoppers anonymously on 0800 555111.