A woman has been punched in the face and sexually assaulted close to a railway station in Bristol.
Police said the victim was jogging on Monday in a grassy area close to Sea Mills station when she saw a man who punched her as she went past.
The victim struggled free after hitting the man.
Det Insp Louise Boyce said: "This was a particularly nasty sexual assault and we're offering the victim all the help and support she needs."
The area is currently sealed off while officers conduct a search.
The offender is described as white, of average build, around 5ft 8ins to 5ft 9ins, with dark stubble around his chin.
He was wearing dark sports clothing and a black baseball cap. He also had a ring on one of his middle fingers.