A train accident in the Alps in southern Germany has left at least four people dead and many more injured, authorities said.

Police said the regional train headed for Munich appeared to have derailed shortly after noon in Burgrain - just outside the resort town of Garmisch-Partenkirchen, from where it had set off.

Three of the double-deck carriages overturned at least partly, and people were pulled out of the windows to safety.

The cause was not immediately clear.

Police said on Twitter that four people were killed. They put the number of injured at about 30, 15 of whom were seriously injured and taken to hospitals.

It was not clear how many people were on the train at the time of the accident.

The line between Garmisch-Partenkirchen and Oberau, north of the accident site, was closed.

The area is near the Austrian border.