"Grid incident occurred at 1 p.m. affecting the Northern, Eastern and Northeastern Grid. System is under restoration," said the official website of the Eastern Grid.
Train services in the region came to a complete halt due to the power failure, a railway spokesperson in Kolkata said.
"About 150-200 trains have been affected by power failure," said a Northern Railway official.
The Delhi Metro suspended service on all six lines as power tripped for the second consecutive day.
Image: Commuters wait for buses outside a Metro station after Delhi Metro rail services were disrupted following power outage in New Delhi, Tuesday, July 31, 2012.