The train driver, a Portuguese national, was among those killed, according to authorities in the town of O Porrino, the nearest to the accident.

Another crew member and 63 passengers were on board the train, which crashed close to a station around 20 minutes into its journey between the Spanish city of Vigo and the Portuguese city of Porto.

Regional authorities said 47 people were taken to hospital.

The accident, which happened just before 9.30am local time, resulted in the train's front carriage flipping onto its side and ramming up against an electricity pylon next to the track.

Spain's state rail manager Adif said it had launched an investigation into the cause of the accident. Spanish media said the train had hit a bridge after coming out of a curve.

The passenger train belonged to Portuguese state rail company Comboios, Spanish authorities said.

In 2013, 80 people were killed in Spain's worst rail disaster in decades when a high-speed train went off the tracks and slammed into a wall near Santiago de Compostela in Galicia.

Reuters