It was witnesses who alerted police at 10am on Saturday when they heard screams and noise from an apartment.

Did the perpetrator and the person who was robbed know each other?

"We can't go into details, but the two people were in the same apartment, that is, no one broke in," says Åsa Wallentin, press spokesperson for the Stockholm Police.

No gripes

The police have held interrogations with several witnesses at the scene, but at present no arrests have been made for the suspected robbery. Parts of the property are blocked off for carrying out a technical examination.

A preliminary investigation into attempted murder and serious robbery has been initiated.