The accident occurred at 9.25 am local time (8.25 in Lisbon).

One of the four victims was the Portuguese train driver and “there are dozens of other victims,” the local deputy Mayor told Spanish television.

The train was carrying 63 passengers and the accident occurred near the Spanish station of O Porriño. An Adif spokesman, speaking to Spanish newspaper El País, said that the reasons for the accident were unknown.

Spanish train company Refe Nacional Ferroviária de Espanha (Renfe) told Lusa on Friday morning that the train was owned by Portuguese railway company CP, had a Portuguese driver and 63 passengers on board.

The Vigo to Porto service has been jointly operated by Portuguese rail company CP and Spain’s Renfe since the “Celta” line was opened in 2011.

Renfe would not confirm if any of the people on board had been injured or killed, as reported by a number of news outlets.

A source from CP confirmed to Lusa that the driver was Portuguese and the crew were a mixture of both Portuguese and Spanish nationals.

The Voz da Galiza newspaper reported 12 people had been injured, two of which seriously.