A 23-year-old woman was indecently assaulted in an alley way in a Leicestershire town, police have said.
The attack happened just before 2100 GMT on Thursday in an alley way between Tamworth Road and Avenue Road in Ashby.
Police said the victim was approached from behind by the suspect who pulled her to the ground and indecently assaulted her.
The attacker then ran off in the direction of Avenue Road.
Police said the woman sustained an injury to her left eye.
Det Insp Simon Shuttleworth, of Leicestershire Constabulary, said: "This incident has been very upsetting for the victim and has left her feeling shaken.
"It's important we build a complete picture of events and any information you have, no matter how insignificant it may seem, could be vital to the investigation.
"If you do recall any details we'd urge you to get in touch."
The suspect is described as white, about 5ft 6in (1.67m) tall and of slim build.
He was wearing dark clothing and described as speaking in a high pitched voice.