A bus carrying travelers from Denmark to Austria skidded off a road in northern Germany and flipped over on Friday, injuring more than 20 people, including one seriously.

Axar.az informs, citing AP, The bus, operated by Flixbus, left the Autobahn motorway in the pre-dawn hours on an exchange leading to the city of Röbel, about 140 kilometers north of Berlin, police said.

The cause of the accident was under investigation.

Twenty-three people were injured on the bus carrying 53 passengers and two drivers from Copenhagen to Vienna, according to Flixbus.

Rescuers took about two hours to extract one seriously injured victim. Emergency services, the fire brigade, and a rescue helicopter responded.

Authorities sealed off the area of the road throughout Friday morning.

Flixbus expressed great dismay that the bus crashed and said it was working with authorities to determine the cause of the incident.