NEW DELHI - Power supplies have been largely restored in India after its worst-ever blackout, which left hundreds of millions of people across more than half the country without electricity.
The blackout, which lasted for well over 10 hours, began at 1.04pm (1734 AEST) on Tuesday and affected 19 states as well as the capital New Delhi, paralysing rail and road transport.
In a statement late Tuesday the state-run Power Grid Corp, which controls the country's transmission network, said electricity had been fully restored in New Delhi and the northeastern region.
The company says power had also been restored in up to 82 per cent in the northern region, and 65 per cent in the eastern region.
More than 200 coal miners were trapped deep underground in scores of pits in West Bengal for around six hours when the power cut left them unable to operate their lifts.
Mining company officials said the workers had been guided to locations where there was good ventilation and waited until the power returned and they could be brought back to the surface.
"All the miners have been rescued. They are all safe and are returning home," said Eastern Coalfields Ltd. general manager Niladri Roy.
The Press Trust of India news agency reported that 65 miners had been similarly trapped in neighbouring Jharkhand state.
Federal Power Minister Sushilkumar Shinde told reporters that the monster outage was caused by states drawing power "beyond their permissible limits".
There appeared to have been a domino effect, with the overloaded northern grid drawing too heavily on the eastern grid which in turn led the northeastern network to collapse.
An area stretching from the western border with Pakistan to the far northeastern state of Arunachal Pradesh next to China was affected, with the huge cities of New Delhi, Kolkata and Lucknow suffering without supplies.