25,500 Berlin households without power four days after grid attack

Repair work to restore electricity and heating to parts of south-western Berlin following an attack on the grid continued on Tuesday as tens of thousands were left in the dark for a fourth consecutive day in the snow-covered German capital.

Some 45,000 households and over 2,200 businesses in the city's Nikolassee, Zehlendorf, Wannsee and Lichterfelde neighbourhoods were cut off early Saturday after high-voltage cables leading to a power station were set ablaze by what Berlin authorities believe was a group of left-wing militants.

Some 19,500 households and some 1,000 businesses have since had their power restored, but operator Stromnetz Berlin said it may take until Thursday for everyone to be back on the grid as repair work is complex.

Police, firefighters and the military have been deployed to the affected areas to assist those who were not able to shelter with family or friends in other parts of Berlin, where temperatures were below freezing.

Hospitals were able to continue operations thanks to emergency generators and have since seen their power restored, while 72 of 74 affected care homes are also being supplied again, according to Stromnetz Berlin.

In a letter of responsibility posted online on Sunday, the left-wing extremist Vulkangruppe (Volcano Group) says it "successfully sabotaged" a gas power station in Lichterfelde.

The group said its primary aim was to target the fossil fuel industry, noting that the action "resulted in power outages in the more affluent districts of Wannsee, Zehlendorf and Nikolassee."

"We apologize to the less affluent residents of south-west Berlin," it said.

Berlin authorities consider the letter to be authentic, with Mayor Kai Wegner describing the attack as an act of terrorism.