An activist group targeted Tesla’s German gigafactory this week, news agencies report.

Production was halted at the site near Berlin, after it was left without power when a nearby electricity pylon was set on fire. Workers on the site were evacuated, and the blaze was extinguished by the fire brigade.

The so-called ‘Volcano Group’ published a letter claiming responsibility, citing that the plant has become known for ‘exploitation’, among other environmental concerns, such as allegedly contaminating the groundwater.

In the lengthy letter, the group said: “We sabotaged Tesla” because it “eats up earth, resources, people, labour and spits out 6,000 SUVs.”

Responding to the incident, Tesla CEO Elon Musk posted on X:  "These are either the dumbest eco-terrorists on Earth or they're puppets of those who don't have good environmental goals.”

The arsonist attack comes as Tesla’s German plant is looking to expand, doubling the 500,000 vehicles it makes in a year.

A number of protestors against the expansion were camping in a nearby forest. One group, who called themselves ‘Robin Wood’, spoke to the BBC and said it “had nothing to do with the fire.”

In statement released to the AFP news agency, a Tesla spokesperson said: "We are currently unable to say when production can be expected to resume.”