A fire broke out in an apartment in a multi-family house in Tyresö.
The fire is believed to have started inside an apartment and smoke spread to other apartments in the stairwell.
Three people were taken to the hospital with minor smoke injuries.
The fire department was able to quickly extinguish the fire. The police assisted the fire department with measures such as cordoning off the area around the fire.
Update 19:50:
The police have launched an investigation into reckless endangerment. The apartment is cordoned off for technical examination.
One person was taken to the hospital with minor smoke injuries. A dozen people with smoke injuries were checked by ambulance personnel on the scene.
The fire department is working on site to ventilate the stairwell.