The collision, which involved two Stadler Flirt trains operated by Transdev subsidiary Meridian, occurred at 06.48 CET between Kolbermoor and Bad Aibling on the Rosenheim - Holzkirchen Mangfall Valley Line south of Munich. The 37km line is largely single track and equipped with PZB 90 cab signalling and train protection. Speaking at a press conference, Bavaria's interior minister Mr Joachim Herrmann confirmed the trains involved in the accident were the 06.10 Holzkirchen - Rosenheim, which was due to reach its destination at 06.49, and the 06.43 Rosenheim - Holzkirchen. According to the timetable, the two trains should have met at Kolbermoor station.

Federal transport minister Mr Alexander Dobrindt said the trains were both travelling at around 100km/h at the time of the accident, the worst on Bavaria's rail network for more than 40 years. 

According to local broadcaster Bayerischer Rundfunk, the drivers and guards on both trains were among the fatalities.

"We are deeply shocked that something like this could happen," says Mr Christian Schreyer, CEO of Meridian's parent company Veolia Verkehr. "Our thoughts are now with the victims and their relatives. The rescue workers on site are doing everything humanly possible to provide assistance at the inaccessible location."

The Federal Railway Accident Investigation Board (EUB) has launched an inquiry and event recorders have been recovered from both trains.