Several improvised explosive devices were found at a power substation near Germany’s Jänschwalde coal-fired power plant in Brandenburg after what authorities believe was a deliberate attack.

The attackers reportedly fired rockets at the facility, damaging several power lines and prompting emergency crews to respond.

The grid operator 50Hertz said there was a brief interruption of service, but all power lines have since been restored.

Police said no one was injured and that the apparent goal may have been to cause a large-scale power outage in the surrounding area, Euro News has reported.

Authorities are investigating the incident, which remains a developing case as officials work to determine who was responsible and their motive.