For those waking up expecting a calm and quiet morning -- well -- that's not the case. There's news that a major train network in northern Germany came to a screeching halt due to "sabotage," Deutsche Presse-Agentur (dpa) tweeted.

"Sabotage to cables which were vital for train traffic, meant Deutsche Bahn had to stop trains running in the north this morning for nearly three hours," state-owned rail operator Deutsche Bahn said.

Service was disrupted through the state of Lower Saxony and the city-states of Bremen and Hamburg. Also, international rail lines between Denmark and the Netherlands.

Der Spiegel magazine was more specific about the "sabotage" and said communication network cables for Deutsche Bahn were severed in two places.

This isn't the first time "sabotage" has been in the news. The disruption comes after EU leaders say acts of "sabotage" blew up the Nord Stream gas pipelines that run under the Baltic Sea from Russia to Germany.

NATO and EU stressed that member countries need to secure critical infrastructure against potential attacks.