LISBON - A PORTUGUESE train popular with tourists derailed on Friday killing one person and injuring 25 with many passengers still trapped, emergency services said.

Emergency officials in the northern town of Braganca said there were reports the train derailed after an explosion in the first carriage, Lusa news agency reported.

The train was carrying 47 people when it came off the rails in rugged countryside close to Braganca. Ten of the injured were said to be in a 'serious' condition, the civil protection service said in its provisional toll.

The local Ansiaes radio station said the dead victim was believed to be a child.

'Several passengers are still trapped,' said a fire brigade official at Carrazeda de Ansiaes, which was handling the accident.

Four helicopters were used to transport the most seriously hurt alongside a fleet of ambulances. About 100 firefighters were struggling to cut passengers free.

The train was going from Tua to Mirandela and derailed near the village of Brunheda just after 11 am (1000 GMT).

The line is popular with tourists because it passes along the Tua river and gives spectacular views of the Douro winegrowing region.

The Ansiaes radio station said that the train derailed on a slope but luckily came off on the mountain side, narrowly avoiding falling into a ravine.

Three people died when a train derailed on the Tua line in February 2007.

That train, which had only been carrying five passengers, fell into the ravine. -- AFP