A German high-speed train travelling from Cologne to Munich caught fire early on Friday, prompting the evacuation of all 510 passengers without injury before flames ripped through two carriages and burned them out.

Mass-selling daily Bild said a policeman travelling on the ICE train smelled smoke and activated the emergency braking system, "averting catastrophe".

Operator Deutsche Bahn said it had closed the high-speed line between Cologne and Frankfurt as a result of the fire and would divert trains travelling that route, adding 80 minutes to the journey time.

The cause of the fire was being investigated, it said.