The regional train was traveling in the direction of Munich when it derailed near Burgrain, north of Garmisch-Partenkirchen, a ski resort in the Bavarian Alps.
”The number of fatally injured in the train accident unfortunately increases to four people,” Upper Bavaria South Police, which have taken over rescue efforts, tweeted Friday afternoon.
Police said of the approximately 30 injured passengers, 15 have sustained serious injuries and were admitted to hospitals in the surrounding area.
Stephan Scharf, an official from the district of Garmisch-Partenkirchen, had told CNN earlier that 60 people were receiving medical treatment.
The accident occurred on the last day of school before the Pentecost, a religious holiday celebrated in Bavaria. It was not immediately clear how many students were on board when the train came off the tracks.
Photos and videos from the scene shared on social media show carriages of a double-decker regional train rolled down an embankment and caught in leafy trees, as rescue workers carried people away on stretchers.
Prosecutors and police have launched an investigation into the cause of the accident, police told CNN.