A passenger train has derailed in Spain's north-western Galicia region, killing four people and injuring 47 others who were taken to hospitals, authorities said.

The accident occurred at 9.30am local time (07.30GMT) in Porrino, about 280 miles north-west of Madrid, the Galician regional government said.

The train had three cars and was approaching Porrino station when it derailed.

The front car came completely off the track and smashed into an electricity pylon next to the line, crushing the engineer's cab and leaving the car leaning to one side.

The back two cars were partly off the tracks. Emergency services dispatched doctors on helicopters to the scene.

The train was carrying 63 passengers, the engineer and a ticket collector, state rail company Renfe said.

The train left Vigo at 9.02am and was scheduled to arrive in Porto in neighbouring Portugal two hours later. It belonged to Portuguese rail company Comboios de Portugal.

Adif railway infrastructure company said it has opened an investigation. The derailment occurred on a straight stretch close to Porrino station.