BERLIN (Reuters) - A far-left militant group calling itself "Vulkangruppe Tesla Abschalten", or "Volcano group shutting down Tesla", has claimed responsibility for the suspected arson attack on a power pylon near Tesla's car factory outside Berlin on Tuesday.

The attack resulted in a production halt that is expected to last several days.

In a letter posted on website kontrapolis.info, the group said destroying Tesla was "a step on the path to liberation from patriarchy".

Police said they were aware of the letter, which was signed "Agua De Pau", the name of a volcano in the Azores, and that they were checking its authenticity, which would take several days.

GERMANY'S 'VOLCANO GROUPS'

In a 2019 report, Berlin authorities listed Vulkangruppen, or volcano groups, as left-wing extremist organisations. "Unknown individuals have been committing arson attacks in Berlin under the name Vulkangruppen since 2011," it said.

These have targeted cable ducts on railway lines and in some cases radio masts, data lines or company vehicles, it said.

The suspects usually claim responsibility in letters in which they use names referring mostly to Icelandic volcanoes, such as "Grimsvotn", "Katla" or "Ok", it added.

It is unclear how centralized the groups' activities are. The report said the structure of the letters suggested they were written by an at least partly fixed group of authors.

"A strategy paper from 2015 also points to a fixed structure," the report said.

POLITICAL ALIGNMENT

The groups are ideologically seen to be close to the anarchistic end of the political spectrum.

A 2021 report by authorities in Brandenburg, where the Tesla plant is based, described the Volcano groups as "left-extremist", saying they were trying to gain influence as part of the global climate movement.

OTHER ATTACKS THE GROUPS HAVE CLAIMED

Several arson attacks have been carried out in Berlin in recent years under the umbrella name of the Volcano group, according to the report.

One of these groups claimed responsibility for an attack on the power supply of Tesla's Gruenheide site in May 2021, it said, citing a letter claiming responsibility that was published on a left-wing extremist media platform.

In 2020, a Volcano group claimed responsibility for an arson attack against the Heinrich Hertz Institute in Berlin, which studies digital infrastructure topics, the report said.