"Because of the sabotage, which occurred at the cable communications, necessary for train operation, Deutsche Bahn had to cease the train traffic in the country's north for three hours in the morning," the company's spokesperson was quoted as saying by the news agency.
The German security services are investigating the possibility of sabotage, the Spiegel magazine reported on Saturday.
Earlier in the day, Deutsche Bahn reported technical malfunctions, which caused a temporary halt of long distance trains in Germany's north. The railway operation was restored later but the company warned of possible delays.
The malfunction of the Global System for Mobile Communications (GSM-R) may possibly serve as the reason of the incident, the report said, adding that the technical failures affected both intercity and regional transportation operations.
It was impossible to contact the engine drivers and staff as the network failed to connect transport and infrastructure, it added.