A car rolled off the E4 south of Nyköping in the morning after hydroplaning. Five people were taken to hospital, three of them seriously injured.
The alarm about the accident came in at 04.49. The car had hydroplaned and rolled out into a field.
Emergency services closed the road completely during the response. Anna Larsson, the duty officer, said they shut down the E4 entirely when they arrived.
The road reopened at 06.15. Police said three of the five people in the car were assessed as seriously injured.