Berlin - German railways company Deutsche Bahn said Friday it would idle the most modern type of its bullet trains, amid fears that the axles of the ICE T trains are cracking.

It blamed the major disruption in German passenger services beginning Saturday on the manufacturers of the swift electric trains.

The consortium of Siemens, Alstom and Bombardier refused to provide "reliable data" on the safety of the axles, said Bahn chief executive Hartmut Mehdorn.

A cracked axle was blamed earlier this year for a low-speed ICE derailment at Cologne station in which nobody was hurt.

Passengers have worried since that an axle might fail while one of the trains is moving at the normal cruising speed of between 200 and 300 kilometres per hour.

Rail movements have been disrupted for the past two weeks after the frequency of checks on both ICE T and ICE 3 trains was stepped up when a further crack was found.

"Safety has the absolute priority," said Mehdorn Friday. He did not say how long the stoppage would last.

The ICE T is a model which tilts slightly on curves. Other models of the bullet-nosed red-and-white ICE trains - the abbreviation stands for intercity express - were not grounded.

Among routes likely to face delays are Hamburg-Berlin, joined by a popular hourly service that takes just 95 minutes, and a route between the financial centre of Frankfurt and the Austrian capital Vienna, which also employs the ICE T model.

Bahn said a late Thursday derailment by a slow-moving empty ICE train in Hamburg station appeared to have a different cause, human error. (dpa)