The 25-year-old woman was in a pizzeria in the eastern suburbs of the central Swedish town of Västerås on Saturday evening when three men turned up and appeared to abduct her against her will.
According to a witness the woman became agitated and then scared out of her wits when she saw the men through the window, approaching the restaurant. The restaurant owner was threatened with a gun and had his mobile telephone stolen by one of the men as the group seized the woman and took her with them.
The witness was unable to see if there was a car waiting outside or how the group got away.
The 25-year-old is reported to be a Gothenburg resident, but police had not yet identified the woman early on Sunday morning.