An ATV accident in Oslo has left one person seriously injured and two others with minor injuries.

The incident occurred when a six-wheeled ATV rolled down a ski slope in Sørkedalen, Oslo, during the "Oslos Bratteste" event.

The driver, a man in his 30s hired for event setup, was seriously injured and taken to Ullevål Hospital.

The two passengers, both 13 years old, sustained minor injuries and were sent to a local clinic for examination.

Witnesses reported the ATV rolling several times down the steep slope.

Police have seized the vehicle for investigation to determine the cause of the accident.

The event organizer expressed concern and stated that such an incident had never occurred in the 15 years of the event's history.