Sixty of the first generation Inter City Express trains built in 1991 were taken out of service on Friday. As many as 15 were returned to service after a routine inspection, but the second round of tests was called after it emerged that there had been no ultrasound examination of the wheels.

Rescuers have been working around the clock to find the victims

"In order to rule out any further risks to the public we have decided to immediately call in all the ICE trains of this type for an additional ultrasound investigation," said Johannes Ludewig, the chairman of German Railways.

Investigators have identified a broken train wheel as the most likely cause of the accident at Eschede in north Germany, when a train smashed into a bridge. Parts of a wheel were found 6km (4m) ahead of the bridge.

"There are strong indications that this damaged wheel played a part. So we want to act now and carry out these tests and not wait until the final report," Mr Ludewig said.

Road bridge collapsed

Evidence has suggested that a wheel, which could have broken from material fatigue, may have caused the carriage directly behind the locomotive to derail.

The Hamburg-bound train was travelling at 200km/h (120mph) when the locomotive uncoupled from the train, which then hurtled into a road bridge as the carriages behind jack-knifed into one another.

The road bridge collapsed on several carriages, crushing the passengers inside.

Five more bodies

The search for victims was supposed to end on Saturday, but rescuers found four more bodies overnight in the debris. Police delayed their investigation into the cause of the accident to let rescuers search for more victims.

"We were surprised to find another body under the remnants of a train carriage," a rescue spokesman said. "As a result we have temporarily suspended the criminal investigation to continue the search for more victims."

Although no more victims are believed to be left in the wreckage, rescue workers are still toiling at the scene.

"They are searching the sand shovel by shovel and are even sifting the sand," said Klaus Rathert, the head of the rescue operation.