A woman was sexually assaulted as she walked home after a night out with friends in the early hours of Sunday morning in Forest Town.
The assault took place shortly after 2.30am when the woman was approached from behind by a man in Main Avenue.
The victim was dragged into an alley and sexually assaulted.
The woman, who had been out with friends in Mansfield town centre, had walked along Bath Lane, Ravensdale Road, Sherwood Hall Road, Clipstone Road West and onto Main Avenue towards Forest Town.
Her attacker, who spoke with an eastern European accent, fled the scene on foot in the direction of Clipstone Road West.
He was wearing a distinctive short grey coat with reflective strips on his back.
Officers are appealing for anyone who may have seen the offender or the victim in the early hours of Sunday to come forward with information.
Temporary Det Insp, Rich Monk, said: “Thankfully, these kinds of attacks by strangers are rare and we will be thoroughly investigating to help identify the man responsible, as well as continuing to support the victim and increasing our patrols in the area to reassure residents.”
If you have any information that you think may help, please contact Notts Police on 101 or call Crimestoppers anonymously on 0800 555 111, quoting incident number 132 of 14th December.