The clock was 11:30 when the police were alerted about a "serious situation" at an address in a residential area in Viby, Sollentuna. After an initial check, more patrols were ordered to the scene and barricades were set up, the police write on their website.
When they entered the apartment, a severely injured person was found who was taken to the hospital by helicopter.
In the afternoon, it was announced that two people were dead, a 50-year-old man and a 45-year-old woman, and that they had a relationship.
We are not looking for any suspects. We are not releasing more information about the sequence of events at present, says the police's press spokesperson Nadya Norton.
According to information provided to Aftonbladet, it was allegedly a suspected hostage situation where shots were fired, but the police deny the hostage reports.
Residents in the area described dramatic scenes to Aftonbladet.
They have blocked off the road at the top, there are police officers on all streets with helmets, says a witness to the newspaper and tells about a dozen police cars and ambulances on the scene.
A witness tells TV4 News that police "ran out of the cars towards a villa".
An investigation into murder has been initiated.