The suspect, identified by German media as Daniel V, is believed to have written letters claiming responsibility for attacks that have struck regions including Brandenburg, Saxony and North Rhine-Westphalia over the past week, according to police in Cologne.
Officers said they discovered several launch devices on high-voltage lines near the Weisweiler plant on Monday, along with another confession letter. The attacks have followed a consistent pattern: suspects used rockets to shoot wires across high-voltage cables, causing short circuits.
Explosives found during Tuesday's arrest are being examined by a bomb disposal expert, and police are checking whether any additional devices remain undiscovered in the surrounding area. Bomb squads have been deployed to secure the scene.
Prior to the arrest, police had warned of a coordinated campaign targeting critical infrastructure. The investigation remains ongoing, with authorities working to determine whether the suspect acted alone or with accomplices.