Rescue workers lift bodies from the tangled wreckage

ESCHEDE, Germany (CNN) - Germany said Saturday that ICE high-speed trains of the type that crashed and killed 102 people on Wednesday would be pulled from service a second time for more thorough tests.

Transport Minister Matthias Wissmann told a news conference in this northern village that ultrasound tests were agreed at a meeting of government and railway officials.

"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," he said.

Sixty of the first generation Inter City Express trains built in 1991 were taken out of service on Friday and as many as 15 were returned to service after a routine inspection with the naked eye, but they were not subjected to key ultrasound tests.

"Nothing is going to be swept under the carpet," Wissmann said. "Safety must come before economic interests."

Deutsche Bahn chairman Johannes Ludewig was quoted in the German news magazine Focus as saying the railway might install an early warning system in future ICE models.

Investigators search for clues to the cause of the accident

Experts have said that such a system is used to detect problems with the wheels that could lead to a derailment.

Wheel failure suspected in crash

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

Authorities have confirmed that parts of a broken ICE wheel were found some six kilometers (four miles) ahead of the bridge. The train is believed to have derailed at a switch 300 meters (yards) before the bridge.

The locomotive uncoupled from the train, which then hurtled into a road bridge as the cars behind jack-knifed into one another. The road bridge collapsed on several cars, crushing the passengers inside.

The round-the-clock race to retrieve the dead from the debris continued Saturday after a 150-ton slab of concrete was hoisted clear and four bodies were found overnight, bringing the death toll to 102.

Discovery of 4 bodies prompts renewed search

The discovery of more bodily remains prompted police to interrupt their accident investigation while search crews looked for more bodies.

A spokesman for the search and rescue headquarters in the nearby town of Celle said three dead were found in a flattened first-class compartment.

Hours later another body was found in the debris. Five badly injured people have died in hospitals, bringing the toll to 102.

Correspondent Bill Delaney and Reuters contributed to this report.