Police, rescue services and an ambulance were called to an apartment in Malmö at 2 p.m. on Thursday.
"At the scene we found a seriously injured woman who was taken to hospital by ambulance. The woman has now died from her injuries," police spokesman Patric Fors said earlier.
Three people who were in the apartment were arrested. A man and a woman in their 30s were later released, while a man was detained, the police wrote on their website.
