An arson attack caused damaged to the train line between Hamburg and Bremen but no one was injured, German police said on Monday.
Early in the morning, unknown perpetrators deliberately set fire to a cable shaft on the railway embankment near Bremen’s Bürgerpark using an incendiary agent, police said.
Germany’s state security agency is investigating whether the crime was politically motivated.
Initially, no high-speed trains between the western state of North Rhine Westphalia and Hamburg were able to travel via Bremen Central Station.
Later, long-distance trains travelling to North Rhine Westphalia were able to stp there again though with some delays, according to a spokeswoman for German rail operator Deutsche Bahn.
The high-speed rail services from the south-west heading to Hamburg were still diverted in the afternoon. Disruption may last until the evening, the company said.
Regional trains on the Hamburg-Bremen line are also affected by the disruption.