London: A major power failure hit southern London on August 28, severely disrupting commuter traffic and stranding hundreds of thousands at the peak of rush hour, officials said.

"There will be travellers underground. I don't know the extent (of the disturbance) yet. It's at the end of rush hour, the peak period, so it's a busy time," a spokesman for the London Underground said.

London Mayor Ken Livingstone called the blackout a "disgrace" and said his office would begin an investigation immediately into the causes. He told Sky News there was no sign of a terrorist attack.

Up to half a million people could have been affected by the power cut, 250,000 of them commuters on the public transportation system, he said.

The blackout came exactly two weeks after a massive power failure affected tens of millions of people across much of the North Eastern United States and South Eastern Canada.

"We have lost supplies to large parts of South London in the last few minutes as a result of a National Grid failure supply in the south London area," a spokesman for EDF Energy, which supplies power to the London area, said.

"It's difficult to predict how long this is going to take. National Grid has got to get the circuit back," he added.

Approximately an hour after the power failure, which occurred at 6:15 pm (22:45 hours IST), lights were gradually coming back on in London.

Agencies