Two trains have collided head-on on a level crossing north of Copenhagen, leaving five people in critical condition and 13 others injured, according to medical officials.

The collision occurred early Thursday morning on a line connecting the towns of Hillerød and Kagerup in the North Zealand area, involving a total of 37 passengers on board.

Emergency response teams quickly evacuated those injured, with Tim Ole Simonsen from the Greater Copenhagen fire department stating that all the affected individuals were transported to hospitals via air or ambulance.

Local mayor Trine Egetved expressed her shock and concern over the accident, highlighting that the local track is frequented by many residents, workers, and students. She emphasized the need to prevent similar incidents in the future.

The collision happened at approximately 06:29 local time, and images released show two yellow and grey trains heavily damaged, facing one another in a wooded area.

Denmark's Accident Investigation Board arrived on the scene to begin an extensive investigation. Inspector Morten Pedersen noted that it was premature to determine the crash's cause but mentioned that they are examining all potential factors, including signaling system failures or human error.

The board's railway unit manager, Klaus Jensen, indicated that investigators are considering multiple hypotheses while Claus Pedersson, safety director at Lokaltog, described the crash as one of the most severe scenarios possible in the railway industry.

In a public statement, Prime Minister Mette Frederiksen expressed her deep concern over the incident, reinforcing the urgency of understanding the factors leading to the crash.

As investigations continue, Pedersen reassured passengers about the competency of the train operators responsible for monitoring train safety, stating that efforts are vital to learn from this tragic incident and ensure such occurrences do not happen again.