The replacement of numerous concrete sleepers at Deutsche Bahn after the train accident in Garmisch-Patenkirchen will slow down train traffic in many places until at least the end of the year.

"The aim is for almost all affected routes to be normally passable again by the end of the year," the group announced on Friday.

"But it is also clear that some of the sleeper replacements will continue into the coming year."

There are currently restrictions for passengers due to the examinations of the components at around 165 points in the rail network.

“The federal states of Bavaria, Saxony, Saxony-Anhalt and Thuringia are primarily affected,” it said.

Report sees manufacturer error

The group announced that some of the sleepers examined had “irregularities in the material properties”.

Several technical reports pointed to a manufacturer error.

Further details were not initially known.

Conclusions about the cause of the accident in Upper Bavaria could not be drawn from these findings, it said.

Investigations are ongoing, but no results have yet been determined.

In the accident in Garmisch-Patenkirchen, a regional train derailed in early June.

Four women and a 13-year-old died in the accident.

There were numerous serious and minor injuries.

A few weeks later, Deutsche Bahn began checking and replacing around 200,000 concrete sleepers nationwide.

According to the railway, the components are the same type of construction as on the section of the train that crashed.

It was initially unclear at how many of the thresholds examined abnormalities were discovered.

Deutsche Bahn estimates the damage incurred to be in the three-digit million range and, according to its own statements, is examining claims for recourse against the sleeper manufacturer.