The attack occurred at 4am on Sunday.
It was around minus 10 degrees Celsius outside and the 22-year-old woman was walking home from the train station in Sundbyberg, a northern Stockholm suburb.
According to the police, five men attacked the woman from behind at the intersection of the Tulegatan and Fredsgatan streets.
She was then raped on the footpath.
"All five men were involved but it is not yet clear whether they all abused her sexually," Stefan Larsson of the Stockholm police told news agency TT.
The Aftonbladet newspaper reports that the attack lasted for one hour.
When the men ran away from the rape scene, the woman managed to call a friend who in turn called the police.
The police only have vague descriptions of the men and said they are "more likely to be in their twenties than in their forties".
"We have some leads and are working on collecting footage from surveillance cameras," Larsson said on Sunday afternoon.
A forensic investigation was underway on Sunday and police were knocking on doors in the hope of finding witnesses.
Larsson told Sveriges Radio (SR) that rapes committed outdoors by several perpetrators who are unknown to the victim are very unusual, particularly during winter.
The woman sustained no injuries during the attack serious enough to require a stay in hospital, and was released by midday. However, she was badly traumatized, according to the Dagens Nyheter newspaper.
Members of the public were encouraged to call the police on 114 14 with any information about the attack.
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