German police said on Wednesday they had launched a terror probe after an attack on an electricity substation near a coal-fired power plant in the east of the country a day earlier.
Several improvised explosive devices were found at the Preilack substation on Tuesday, which distributes power from the nearby Jänschwalde power plant.
Operator 50Hertz said there was a "brief interruption of service" but all lines are now back in operation.
Police said no one was hurt.
Meanwhile, authorities also said they were probing a separate incident at a substation in the western state of North Rhine-Westphalia, which saw power knocked out on some cables, on suspicion of "sabotage."
Police said earlier that they suspected a "deliberate act" damaged the substation in Bergheim near Cologne, the latest in a string of incidents involving critical infrastructure.
Also on Tuesday, Berlin publicly blamed Russia for an attempted drone "attack" at Leipzig airport last month.
In a press conference on Tuesday, Interior Minister Alexander Dobrindt said an assessment of the incident "fits the known pattern of Russian hybrid operations in Europe."
NATO member Germany, which has been a strong supporter of Ukraine in its fight against Russia, has long accused Moscow of targeting it with a campaign of hybrid attacks involving espionage and sabotage, claims the Kremlin has rejected.
Germany has for months reported suspicious drone sightings over military and industrial sites, but an incident at Leipzig/Halle Airport on the night of 4-5 August raised the alarm as a drone found there carried explosives.
Meanwhile, the heads of the European Commission and NATO are meeting in Brussels in response to a string of hybrid warfare incidents in Europe over the summer.
