It was shortly after 10 pm that the police were alerted to Gibraltargatan in Gothenburg due to a riot.
When the police arrived at the scene, several of those involved had left, but one person was left with knife injuries.
Three to hospital with knife injuries
Later in the evening, it emerged that three of the people had visited the hospital with knife injuries.
Several people are said to have been taken in for questioning and an investigation into attempted murder has been initiated.
The text is updated.