Germany’s national railway operator said it halted trains across the country on Tuesday evening because of a problem with a communication system.

Germany’s national railway operator said it halted trains across the country late Tuesday evening because of a problem with a communication system.

Deutsche Bahn said in a brief statement on its website that all trains were being held at stations because of a nationwide problem with the GSM-R digital communication system, which is used for internal communication on the railway network.

There was no immediate information on the cause of the problem.

Deutsche Bahn wrote that its “technicians are working at high pressure” to fix the issue.

It didn’t specify how long that might take or say how many trains were affected.

The Bild newspaper quoted Deutsche Bahn CEO Evelyn Palla as saying that “we are now trying to get the trains into stations so that travelers can disembark. And then we have to fix the problem, which we don’t yet know.”

GSM-R, short for Global System for Mobile Communications-Railway, offers voice and data services needed to operate railways, including communication between train drivers and control centers.

According to the European Union Agency for Railways, it has been introduced across Europe since 2000 as a common standard for railway operations.

The German railway system has on rare occasions in the past halted all or most trains, but because of storms rather than for technical reasons.