At least four people were killed when a train derailed in a wooded area in Germany, spilling two carriages from the tracks.

The regional train in the southwest was carrying about 100 passengers of which several were seriously injured, police confirmed.

Two carriages left the tracks between the towns of Riedlingen and Munderkingen, near the corner of Germany that borders France and Switzerland.

Helicopters arrived shortly after the accident to transport the injured to hospitals in the area, and emergency doctors from nearby hospitals were alerted, according to local TV station SWR.

The train was on a roughly 90 km (55 miles) route between Sigmaringen and Ulm.