The accident took place on the A9 motorway on Wednesday morning and it was closed in both directions.

There were "numerous casualties", police have said.

The bus overturned on the busy motorway that connects Berlin to Munich, although "the exact circumstances of the accident are not yet known", said Flixbus, the vehicle's operator.

Rescue helicopters and ambulances also attended the scene.

Some 53 passengers and two drivers were on board the bus which was travelling from Berlin to Zurich.

The double-decker vehicle was later turned upright to continue the recovery effort, German news agency dpa reported.

The Leipziger Volkszeitung newspaper reported the nearby Deaconess hospital had prepared for the casualties, having reserved operation rooms and by putting CT scans on standby.

Flixbus told Sky News it "regrets" to confirm the accident and its current focus is on providing support to all passengers.

It added: "For uninjured passengers, we offer onward transportation to their desired destination and are also personally available to provide support."