BERLIN: Improvised explosive devices were used on Tuesday (Sep 1) in a sabotage attack near a coal-fired power plant in Germany, with several electricity lines damaged and supply briefly interrupted, police and a grid operator said.Several makeshift bombs were found around 8am (2pm, Singapore time) at the Preilack substation, which distributes power from the nearby Jaenschwalde plant, a police spokeswoman told AFP.At least one of the devices detonated but others failed to go off, she said, adding that no one was hurt and there was no major blackout in the area, about 100km southeast of Berlin.Power plant operator LEAG said in a statement that "an attack was carried out" at the substation.Show MoreShow LessIt also said there was a "technical failure" in a unit at the power plant, and a possible connection with the incident was being investigated.Grid operator 50Hertz claimed that unidentified perpetrators damaged several lines in its grid."There was a brief interruption of service. All lines are now back in operation. The general power supply is currently not affected," it said in a statement.The police spokeswoman said an investigation had been launched to determine who was behind the incident.There have been several arson attacks in and around Berlin in recent times, with far-left militants often claiming responsibility.In January, an electricity outage left tens of thousands of homes and thousands of businesses without power for nearly a week in the middle of winter in the southwest of the German capital.The far-left "Vulkangruppe" (Volcano Group) claimed responsibility for the arson attack on high-voltage cables that caused that blackout.It also claimed to be behind two sabotage attacks targeting a Tesla electric car factory just outside Berlin.Germany, a major supporter of Ukraine in its fight against Russia, is also on high alert for sabotage and espionage plots linked to Moscow.