Volcano Group, a self-identified arsonist, caused a power outage at Tesla's German factory, causing potential damages approaching $1 billion.
The incident also affected more than 60,000 residents in Brandenburg and parts of Berlin when a high-voltage power mast near the factory caught fire.
This attack concerns protecting critical infrastructure from vandals and criminals.
In a statement, the group claimed that destroying the Gigafactory and removing figures like Elon Musk is a step towards liberation from the patriarchy.
Tesla's senior director, Andre Thierrig, estimated the economic loss from the production shutdown to be in the "high hundreds of millions" of euros, as around 1,000 vehicles a day cannot be produced.
Tesla's factory in Grünheide, the first in Europe, produces the Model Y crossover for most European left-hand drive markets, including Germany.
Emergency power still requires local substations to be connected to the grid.
However, the attack broke the lines between the mast and the substation, causing the backup system to fail.
As a result, all 12,500 employees had to be sent home, and production is not expected to resume this week.
The volcanic group previously targeted the Tesla factory's power supply in May 2021 during its construction phase.
Brandenburg's industry minister, Jörg Steinbach, expressed support for Tesla and vowed to prevent further attacks.
The incident is the latest in a series of challenges for Tesla's European factory, including protests against its expansion and reports of pollution in the water supply.
Despite Elon Musk describing the attackers as "the stupidest eco-terrorists on Earth", they have not been caught.
Their method involves setting fire to electronic cables in remote locations, disrupting various services and operations.
The Federal Association for the Protection of Critical Infrastructures in Germany criticized the lack of protection for such targets.
The event is expected to reduce Tesla's unsold inventory in Europe without the need for additional price incentives.