A fire in a switch box has caused massive delays and chaos on a main train route in Italy on Monday.

Traffic on the high-speed line between Florence and Rome temporarily came to a complete standstill. Thousands of travellers were left stranded at railway stations.

Trains were up to four hours late and more than 40 were cancelled completely, the state railway company RFI said. The delays were caused by a fire in a switch box to control the high-speed trains in Rovezzano near Florence. The company said it suspected arson.

Interior Minister Matteo Salvini said he wanted to know whether the fire was started by members of the anarchist scene or by opponents of the planned rail link between Turin, Italy and Lyon, France, which has come under fire for its multi-billion-euro price tag.

Whoever started the fire deserves ‘years’ in prison, Salvini said.

From 5 am to 8 am (0300 to 0600 GMT) the entire line between Florence and Rome, which connects the north and the south of the country, was closed.

Problems were expected to continue throughout the day, RFI said, with travellers as far as Turin experiencing hours-long delays.

Travellers in Italy can also expect delays on Wednesday, as trade unions called for strikes on public transport, taxis, car rentals and ferries.