Ten people were killed when two trains collided head-on in southeast Germany on Tuesday, police said, adding that more than 100 people were injured.
The collision took place on a single track and one train was derailed, said a police spokesman.
Among the 108 injured, 18 were in serious condition, after the crash at a peak commuter time of 6:48 am near Bad Aibling in a Bavarian spa town about 60km southeast of Munich.
The cause was unclear and police said that, alongside the rescue effort, investigations into establishing the circumstances of the crash had started.
Dozens of rescue teams were on site and helicopters carried some of the injured people to nearby hospitals. The area was sealed off.
The trains' operator, Meridian, is part of French passenger transport firm Transdev, which is jointly owned by state-owned bank CDC and water and waste firm Veolia.
Transdev said in a statement that management and staff were terribly shocked by the "exceptionally serious accident" and that Chief Executive Jean-Marc Janaillac was at the scene.
German Transport Minister Alexander Dobrindt, also at the site of the crash, said it was unclear whether it had been due to a technical failure or human error.
Meridian runs train, tram and bus networks in 19 countries and had revenues of 6.6 billion euros in 2014.
State-owned Deutsche Bahn is responsible for the track. The line has a system that makes a train brake automatically if it goes through a red light.
Police were to hold a news conference at 12.00 local time (1100 GMT), but it was delayed to a later time.