A woman was touched inappropriately on Overstone Road, Northampton at 9.40 pm on Monday, police have reported.
A spokesman for Northamptonshire Police said: “The victim left the Lamplighter Pub and was walking along the road, when she was approached by a man from behind who touched her inappropriately. He ran off when she screamed.
“The offender is described as white with tanned skin, in his early 20s, around 5ft 8ins tall and of skinny build.
“He had a slim face with pronounced cheeks, black styled stubble and short, dark, shaved hair. He was wearing a grey and white hoody and may have been carrying a drawstring bag,” he added.
Anyone with information can contact Northamptonshire police on 101. Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111.