Gotthard tunnel in Switzerland will be closed for months after freight train derailed

The world’s longest rail tunnel has closed for repairs after a freight train derailed – and it is not expected to open for months.

The Gotthard railway tunnel in Switzerland will be shut until the end of 2023, much longer than was initially anticipated.

The 16 cars that derailed last Thursday caused considerable damage to the tracks and are still stuck inside the tunnel.

Nobody was harmed in the incident and pictures of the scene show wine bottles strewn on the line, among other objects.

Passengers will now have to take the scenic route instead – adding an hour onto domestic journeys, with two hours of delays for international travellers.

The 35-mile (57km) tunnel, which opened in June 2016, cuts through the Alps and provides a high-speed link between northern and southern Europe.

Five miles (8km) of tracks and 20,000 concrete railroad ties are going to be replaced.

As well as transporting passengers, Gotthard is a key passage for cargo – particularly between Germany and Italy – with more than two-thirds of rail freight traffic in the Alps going through the tunnel last year.

One side of the tunnel was unaffected by the derailment and should be operating “in principle” from next week.

It took 17 years to build at a cost of 12.2 billion Swiss francs (£10.8bn) and was designed to slash travel times, ease road congestion and reduce air pollution.