Authorities were able gradually to reconnect many to the network but several days of work were required to repair the damage.
Power was being restored to thousands of households in Berlin on Wednesday that had been without electricity in freezing temperatures for four days following a suspected far-left attack on high-voltage lines, authorities said.
About 45,000 households and 2,200 businesses lost their supply on Saturday morning after a fire on a bridge that carries high-voltage cables over the Teltow Canal, in the southwest of the German capital, affecting an estimated 100,000 people.
Authorities were able gradually to reconnect many to the network but several days of work were required to repair the damage.
Some 25,500 households and 1,200 businesses were still without power on Tuesday, largely in the prosperous Zehlendorf district.
It was the longest blackout in the city since the end of World War II.
Berlin's power network operator said service was gradually being restored on Wednesday to all remaining households, German news agency dpa reported.
Investigators have focused on a written claim of responsibility by a far-left group, headlined "Turning off the juice to the rulers," which said a gas-fired power plant in Berlin's Lichterfelde district had been "successfully sabotaged."
It claimed that the aim of the action was to strike the fossil-fuel energy industry, not to cause power outages.
Germany's domestic intelligence agency said self-styled "Volcano Groups" have been carrying out attacks on infrastructure in Berlin and the surrounding state of Brandenburg since 2011.
A 2024 attack on a pylon that supplies a Tesla factory near Berlin temporarily halted production.
On Tuesday, the German federal prosecutor's office said it was taking over the investigation, citing suspicions of anti-constitutional sabotage, membership in a terrorist organisation and arson.
Berlin's governing mayor Kai Wegner said repairs to the 300 metres of damaged cable would not be completed until Thursday.