Swedish police have opened an investigation into suspected aggravated arson after a fire broke out in the stairwell of an apartment building in Hägerstensåsen, Stockholm.

Police and emergency services were called to Arvodesvägen shortly before 9 p.m. on Friday, September 25, after reports of a fire inside a multi-apartment residential building. The fire was located in the building’s stairwell, where smoke spread through the common area.

According to Stockholm Police, the fire was brought under control relatively quickly and the physical fire damage was limited. However, the incident generated significant smoke in the stairwell, prompting an emergency response from both firefighters and police.

Police said evidence collected at the scene strengthened their suspicion that the fire may have been deliberately started. Investigators have therefore treated the incident as a suspected case of aggravated arson rather than an accidental fire.

A number of investigative measures were carried out during the night. Officers spoke with people in the surrounding area and conducted door-to-door inquiries in an effort to establish what happened before the fire started and whether anyone saw suspicious activity near the building.

As of the latest police update early on September 26, no suspect had been arrested in connection with the incident. Investigators were continuing to search for a person or people who may have been responsible.

Police have also secured material from the location for further examination. A technical investigation is expected to play an important role in determining exactly how the fire started and what materials or methods may have been involved.

One person was evacuated from the building before police and emergency crews arrived, according to local reporting. Police have not reported injuries resulting from the fire, and there were no indications in the latest information that apartments themselves had suffered significant fire damage.

The investigation was formally upgraded to a preliminary inquiry into aggravated arson at approximately 10.09 p.m. on Friday. This means authorities are treating the circumstances as sufficiently serious to warrant a detailed criminal investigation.

Investigators are now examining witness statements, physical evidence and other information gathered at the scene. The purpose is to establish whether the fire was intentionally started, identify a possible motive and determine who may have been responsible.

Police have urged anyone who witnessed unusual activity around Arvodesvägen or Hägerstensåsen around the time of the incident to contact authorities with relevant information. Witness accounts can be particularly important in cases where a fire is suspected to have been deliberately started.

The investigation remains at an early stage. Police have emphasized that the initial information may change as forensic examinations and witness interviews provide additional evidence. No individual has been publicly identified as a suspect in the latest police information.

The case also demonstrates why investigators treat fires in residential buildings seriously, even when the physical damage is limited. A deliberately started fire in a shared stairwell can create smoke and evacuation risks for people living in the building, making the circumstances relevant to both the criminal investigation and public safety.

Authorities will now await the results of the technical examination and continue gathering evidence. Any further arrests or developments will depend on what investigators establish during the ongoing inquiry.