The federal police has launched an investigation into the incident, Transport Minister Volker Wissing told a news conference, according to Reuters. "It is clear that this was a targeted and malicious action," he said.
The disruption immediately raised alarm bells after NATO and the European Union last month stressed the need to protect critical infrastructure after what they called acts of "sabotage" on the Nord Stream gas pipelines.
State rail operator Deutsche Bahn (DB) said in a statement that "Due to sabotage on cables that are indispensable for rail traffic, Deutsche Bahn had to stop rail traffic in the north this morning for nearly three hours."
DB had earlier given the cause of the network disruption as a technical problem with radio communications. Rail traffic was still patchy on Saturday afternoon after being restored, it said, warning of train cancellations and delays.
The disruptions affected rail services through the states of Lower Saxony and Schlewsig-Holstein as well as the city states of Bremen and Hamburg, with a knock-on effect on international rail journeys to Denmark and the Netherlands.
MNA/PR