瑞士发生严重交通事故致28死 其中22名是学生

A catastrophic coach crash that killed at least 22 children and six adults - after the vehicle veered, hit a kerb and then rammed into a concrete wall in a Swiss tunnel - could have been caused by speeding.

Police said the vehicle, in which the 12-year-old schoolchildren were travelling, was going 'considerably faster' than the 63mph speed limit as it careered into an underpass wall on the A9 highway, near Sierre, Valais, close to the border with Italy.

Swiss crash scene investigators told Belgium's Le Soir newspaper: 'The coach was travelling at very high speed. It was going considerably faster than the speed limit on a stretch of road where the speed is limited to 100kmh.'

Dozens more were injured in the 9pm smash, which came as a school party of 52 returned from an Alpine skiing holiday to the villages of Lommel and Heverlee in the Flemish region of Belgium. 

Photographs showed the bus rammed up against the side of the tunnel, the front ripped open, broken glass and debris strewn on the road and rescue workers climbing in through side windows.

Smashed: The wreckage of the bus which crashed into an underpass in Sierre, in the Swiss canton of Valais, killing 28, including 22 children

Devastated: Rescuers next to the wreckage of the bus which crashed into the tunnel wall

Carnage: Bloodstains can be seen down the side of the wrecked vehicle as it is towed away

Police said the bus joined the highway towards the Swiss town of Sierre after coming down into a valley and crashed after travelling 1.2miles on the road. The front of the bus was heavily damaged and blocked people from getting out. The cause of the crash has yet not been determined.

A police statement said: 'The bus hit the barrier stones on the right side of the road. It then hit the tunnel wall front-on in an emergency stop space. Because of the strong impact the bus was badly damaged and several passengers were trapped in the wreckage.'

A further 24 children were injured in the accident. Helicopters were used to fly many of the worst hurt to hospitals in the Swiss cities of Lausanne and Berne.

Police were today describing the 'unprecedented' tragedy as the worst road traffic accident in Swiss history.

The front nearside of the coach 'all but disintegrated', according to one rescuer at the scene. He said: 'Around a third at the front was smashed to pieces - it was complete carnage. The sight was a terrible one.'

Belgian Foreign Minister Didier Reynders told French radio Europe 1: 'It is an event which will really shake the whole Belgian population when they wake up this morning to such extremely sad news.'

The Belgian foreign ministry said the children were pupils at the St Lambertus School in Heverlee and the Stekske School in Lommel, and had been on a skiing trip organised by a Christian trade union.

They had been writing a blog about their trip where they said they had been 'having a great time skiing' and that they were 'looking forward to getting home'.

Children at St Lambertus, who were not on the trip, were informed about the accident at an assembly before classes this morning.

'We don't have words, only deep grief. They were supposed to be back now,' Dirk De Gendt, the local priest who is on the school board, said.

Parents of the victims were due to meet at the school later in the morning and then travel by military plane to Switzerland. 'Some parents know their kids have survived. For others there is no news,' said Belgian police spokesman Marc Vranckx.

Peter Vanvelthoven, the Mayor of Lommel, said: 'It is an incredible blow. There were 22 children from one of our schools on this bus, along with two teachers accompanying them.

'We don't yet know how many of them were victims. We have set up a crisis centre for pupils. Parents and other family of those involved are devastated.'

Belgian Prime Minister Elio Di Rupo said he would travel to Switzerland later today. His spokesman added: 'The Prime Minister has with great horror taken note of the terrible accident that has happened in Switzerland. It is a sad day for all of Belgium.'

The bus was one of three heading back to Belgium from a skiing holiday camp in Val d'Anniviers, a Valais ski resort. It was travelling on a highway towards Sitten from Siders when it crashed into the tunnel wall.

Two drivers in the bus also were killed. Swiss journalist Ruth Seeholzer told the BBC that driving conditions were normal and the two-lane tunnel was not busy with traffic when the accident happened.

Tragedy: Police were today describing the road traffic accident as the worst ever in Swiss history

Head-on collision: As the coach is dragged away by a tow truck, the wall it careered into can be clearly seen

Stricken: Tearful parents of children killed in the bus crash gathered outside Stekske School in Lomme today

Some 200 rescuers worked through the night at the crash scene, while 12 ambulances and eight helicopters ferried the injured to hospital.

The other two coaches in the party continued their journey to Belgium. Jan Luykx, the Belgian ambassador to Switzerland, said : 'This tragedy will devastate the whole of Belgium. All of the victims came from two villages.

The coach belonged to Toptours, a company from the town of Aerschot with an 'excellent reputation', according to Belgian transport minister Melchior Wathelet. The firm, which runs a fleet of 14 coaches, specialises in winter sports and regularly transports passengers from Belgium to Austrian and Italian resorts.

'The scale of the accident is impossible to digest. We are currently focusing on the practical aspects of dealing with this tragedy.' He added: 'The drivers had arrived in Switzerland the previous day before making the return journey. It seems that they had respected the rules limiting driving hours.'

Switzerland's mountain regions have a history of deadly crashes. In 2005, a bus crashed in a Valais ravine, killing 12 and injuring 15.

In 2001, a truck crashed in the Gotthard tunnel under the Alps, causing a blaze which killed 11 people.

Wreckage: A police officer looks at the mangled remains of the bus

Injured: Rescuers carry a stretcher to an emergency helicopter at the entrance of the tunnel.