After the meeting, Tiefensee said "major safety failings" were clearly behind Friday's crash of the high-tech magnetic levitation train.

"Questions of safety that are still unanswered must be clarified as quickly as possible by an independent inquiry," he said.

He added that the two key questions were: "Whether the Transrapid's security measures were adequate, and whether they were applied on the test track" where the accident took place.

The accident was the worst in the history of the train, which is propelled by electromagnetic force causing it to 'float' about one centimetre (half an inch) above the track.

The only example of the monorail train in commercial use is in China, where it whisks passengers from the financial district of Shanghai to the city's Pudong airport at speeds of up to 430 kilometres (267 miles) per hour.

China has for years been discussing plans to extend the system to link Shanghai with the city of Hangzhou.

The head of the Transrapid project in Shanghai, Wu Xiangming, visited the crash site at the weekend.

The southern German city of Munich has also been considering building a Transrapid to ferry people between its commercial centre and airport.

Edwin Huber, the economy minister of Bavaria, warned that the disaster "definitely constitutes a problem, psychologically and politically".

The Transrapid was travelling at 170 kilometres (106 miles) an hour when it collided with a maintenance vehicle, killing 23 of the 31 people on board. Ten people survived, including the two drivers of the service vehicle.

Investigators are increasingly convinced that human error led to the collision.

Under normal operating conditions, the train and the maintenance vehicle -- which is used to clean the track -- should not have been in operation at the same time.

Prosecutor Alexander Retemeyer said the probe was focusing on the control room, where two employees had been surveying the track.

A handwritten entry in a log book had shown that the maintenance vehicle was out on the track so the Transrapid should not have been allowed to start its fateful journey.

The service vehicle had probably not received any order to return to its shed and leave the monorail clear, Retemeyer told a news conference on Saturday.

In any case, the service vehicle should have been visible on computer screens because it was equipped with a GPS positioning device.

The control room operators were still too shocked to be questioned.

It emerged that there had been an accident on the test track two years ago when two maintenance vehicles collided after sliding on black ice, causing minor damage but no casualties.

And a carriage on the Shanghai train caught fire last month but was quickly extinguished.

The backers of the project defended the technology used in Transrapid.

"I remain convinced that this is a safe form of transport technology," ThyssenKrupp chairman Ekkhard Schulz said.

Christian Wulff, leader of the state of Lower Saxony where the accident took place, said the disaster appeared to be the result of "human error and a chain of unfortunate events".

"So it makes no sense to question the technology itself."

Pope Benedict XVI has sent a telegramme of condolences to the Bishop of Osnabrueck, Franz-Josef Bode, in which he wished the injured a speedy recovery.

earlier related report
Germany Rushes To Limit Commercial Fallout From Transrapid Crash
Politicians and engineers rushed to defend Germany's Transrapid project on Saturday as fears grew that a deadly crash involving the high-tech magnetic levitation train may also have killed off its commercial prospects.

Twenty-three people were killed in Friday's accident in northwestern Germany, which investigators said was most likely due to human error.

The accident was the worst involving a magnetic levitation train, a technology which is only in use in China.

German Chancellor Angela Merkel, whose government has been on a charm offensive on behalf of the country's export sector in a bid to shore up a nascent economic recovery, insisted that the Transrapid was a "a safe form of technology".

Christian Wulff, leader of the state of Lower Saxony where the accident took place, also said the disaster seemed to be the result of "human error and a chain of unfortunate events. "So it makes no sense to question the technology itself," he said.

And ThyssenKrupp, which developed the technology together with fellow German engineering heavyweight Siemens, insisted the system was safe.

"I remain convinced that this is a safe form of transport technology," ThyssenKrupp chairman Ekkhard Schulz said.

The high-speed train is propelled by electromagnetic force causing it to 'float' about one centimetre (half an inch) above the track at speeds of up to 450 kilometres (280 miles) per hour.

Its designers say it will slash journey times and revolutionise rail travel.

But for all its technological attractions, its commercial success has been hampered by high costs and frequent problems, and Friday's accident may do little to improve its image.

The only version in commercial use is in China where the train, known as the Maglev, whisks travellers between Shanghai's financial district and the city's Pudong airport along a 30-kilometre track.

Several other countries including Britain, the Netherlands, Qatar and the United States have expressed interest, but none has yet signed on the dotted line. Thyssen and Siemens believe the best advert for the Transrapid would be a link in Germany but even here nearly all the mooted projects have been scrapped except for a possible link between Munich city centre and the Bavarian capital's airport.

Financing for that project had been due to debated by Munich's local council next week but that may now be postponed, said Edwin Huber, economy minister of Bavaria, where Siemens has its base.

The accident "definitely constitutes a problem, psychologically and politically", he warned.

The Transrapid was travelling at about 170 kilometres (106 miles) per hour on the elevated concrete monorail test track in Lower Saxony, northwestern Germany, when it collided with a maintenance vehicle early on Friday.

Thirty-one people were on board when it crashed. Two of the 23 dead were US citizens visiting Germany. Eleven German employees of an energy company were also killed.

Ten people were injured, including the two maintenance vehicle operators. Investigators said the collision was caused by human error, possibly because of a breakdown in radio communication.

"We have to examine if safety measures were sufficient and if they were adhered to at every stage," said Transport Minister Wolfgang Tiefensee, who visited the crash site on Saturday.

Osnabrueck prosecutor Alexander Retemeyer said investigators were concentrating on the control room, where two employees had been assigned to survey the track. They should have been able to see the maintenance vehicle and checked the line was clear before giving the go-ahead to the Transrapid, he said on Saturday.

The maintenance vehicle had been given approval to operate and had probably not received any order to move off the track, Retemeyer told a news conference.

But the control room operators should have been able to see it was still there by checking the log in which all movements relating to the train test-runs were supposed to be entered.

In any case, the obstacle should have been visible on their computer screens because it was equipped with a GPS positioning device, he said.

The investigators also wanted to know why the Transrapid driver had only applied the emergency brakes 50-100 metres (yards) ahead of the maintenance vehicle, even though the latter was the size of a lorry, Retemetyer added.

"We hope we can get an explanation after we've studied the radio conversation between the two locomotives," he said, adding that the control room operators were still in too deep a state of shock to be questioned.

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