"A woman in the vicinity of Bäckparken on Björneborgsgatan must have suddenly been grabbed and held by a man unknown to her.
A passer-by interrupts the incident and alarms ", the police write on their website on Sunday.
The alarm was received by the police at 03:00 and the suspected perpetrator is said to be young, approximately 180 centimeters tall and was wearing a gray hoodie at the time.
According to the police, the woman must have received minor physical injuries in connection with the incident.