I did not realise the full extent of the catastrophe until two railway workers came directly from the tunnel... all they had found was the metal base of the train

Regional governor Franz Schausberger

A huge rescue operation was launched to try to save the passengers, trapped in a tunnel on the 4km funicular railway carrying them up to the popular ski slopes of Kitzsteinhorn.

But intense heat and dense smoke billowing through the tunnel, outside Kaprun near Salzburg, prevented anyone getting close enough to save them.

Austrian Chancellor Wolfgang Schuessel has declared two days of national mourning.

Most of the victims are believed to be Austrian, German and US nationals.

Emergency number for relatives

00 43 654 720 000

Mr Schuessel told the British Prime Minister, Tony Blair, that some of the dead were British.

The Foreign Office in London has issued an emergency number in Austria for people concerned about relatives. The number is: 00 43 654 720 000.

Only a handful of survivors - reported to be Germans - made it to safety through the mountain tunnel.

They emerged shocked and injured. Reports said they had smashed the train's rear window and clambered out.

Rescuers had fought to reach the blazing train from both ends of the tunnel, and through an emergency access point halfway along.

But by the time they reached the scene, the inferno had destroyed virtually the whole train.

"I did not realise the full extent of the catastrophe until two railway workers came directly from the tunnel and told us all they had found was the metal base of the train," state governor Franz Schausberger said.

The regional governor is speaking of a catastrophe of unprecedented proportions

Austrian television reporter

"I have to say that it is one of the darkest and hardest days for Salzburg that we have ever seen."

Many of the dead were "probably young people, who might have decided only this morning to enjoy the day and do some winter sports - some skiing maybe or snowboarding," Mr Schausberger said.

Breaking with emotion

An Austrian television reporter in Kaprun, her voice breaking with emotion, said Mr Schausberger had left them in no doubt about the scale of the disaster.

The line climbs steeply to the tunnel entrance

"He is speaking of a catastrophe of unprecedented proportions. You can imagine what the atmosphere is like here at the moment," she said.

Helicopters raced to the scene, as an operation also involving mountain rescue teams and fire crews swung into action.

Specialist accident and emergency doctors attending a conference in Salzburg were also quickly on the scene.

But it appears the passengers stood virtually no chance of escape from the train, 600m inside the 3,200m tunnel.

"The fire was drawn upwards like in a chimney," a spokesman for the Salzburg state government told Reuters news agency.

One survivor described how victims trapped by the fire "screamed in fear" as they sought in vain to escape the blazing tunnel.

Another eyewitness, Christian Wakolbinger, quoted on the website of Austrian broadcaster ORF, said the smoke was so dense it had even affected people in the mountain station at the top of the railway.

Dense smoke

"The smoke swept up the tunnel so quickly that some people in the Alpine Centre were affected by smoke poisoning," he said.

The blaze broke out at about 0930 local time (0830GMT). The cause has yet to be established.

If the figures are confirmed, the tragedy will be among the worst to have hit European transport systems in recent years.

A fire in the Mont Blanc tunnel between France and Italy in March, 1999, killed 39 people, prompting a wave of concern over tunnel safety.

The funicular was packed with skiers

Two months later another Alpine tunnel was hit - this time the Tauern tunnel near Salzburg, killing one person and injuring 50.

Inspectors who visited 25 major tunnels around Europe after the Mont Blanc blaze found that nearly a third of them had poor safety features.