An alarm was raised in central Stockholm on Friday, as a double-decker bus crashed into a stop in the Östermalm area, injuring several people, according to information from the local outlet Aftonbladet.

According to the Stockholm Region, five people were injured, two of whom were taken to the hospital by ambulance and are in serious condition. Police sources reported that at least two people lost their lives, while the newspaper Expressen speaks of three dead.

Police announced that the investigation launched is treating the incident as negligent homicide, and the bus driver has been arrested. Chaos broke out at the scene, as the crash occurred during rush hour, shortly before 3:30 p.m. (local time).

The spokesperson for Stockholm’s public transport authority, Sofie Gunnarsson, stated that it is a serious incident.

A member of the rescue service who was on the scene estimated that the bus must have been out of service, as there were no passengers inside, and it is believed that the driver felt unwell and lost control of the vehicle.