German authorities are aware of 11 criminal offences committed since 2011 by the left-wing extremist Volcano Group, which claimed responsibility for the recent arson attack on the giant Tesla plant near Berlin.
There have been other arson attacks on cable ducts, transmission masts and power supply lines, a spokesperson for the Interior Ministry said in response to an enquiry, the Sunday edition of the Welt newspaper reported.
Some of the attacks had caused considerable damage, including power cuts, radio network failures and disruption to local public transport.
Earlier this month, perpetrators set fire to a freely accessible electricity pylon in a field in the state of Brandenburg, which is part of the power supply to the Tesla car factory in Grünheide.
This brought production to a standstill for several days. The so-called Vulkangruppe, or Volcano Group, said later that it carried out the attack.
The Federal Public Prosecutor's Office, Germany's highest prosecuting authority, took over the case.
It commissioned the state criminal police to investigate possible anti-constitutional sabotage and membership of a terrorist organization.
Activists have been occupying tree houses in parts of the forest near the factory site in a camp set up at the end of February.
They want to prevent the forest from being cleared as part of the planned expansion of Tesla's only European plant.
Earlier this week, a court rejected a police order that called on activists of the "Stop Tesla" initiative to dismantle their tree houses due to safety concerns. The group had filed an urgent appeal against the order with the court.
Brandenburg's Interior Minister Michael Stübgen has said that he noticed an increasing radicalization among some participants of the action.
Opened in March 2022, the Tesla factory currently employs around 12,500 people.
