NEW DELHI -- India suffered its second huge, crippling power failure in two days on Tuesday, depriving as much as half of the vast and populous country of electricity and disrupting transport networks.
The first power grid collapse, on Monday, was the country's worst blackout in a decade. It affected seven states in northern India that are home to more than 350 million people.
But Tuesday's failure was even larger, hitting eastern and northeastern areas as well.
Both blackouts cut power in the Indian capital, New Delhi.
The power companies that operate the affected electricity grids reported the collapse Tuesday on their websites.
With about 1.2 billion people, India has the second-highest population of any country, behind China.
At least 300 trains have been held up in the affected regions, said Anil Kumar Saxena, a spokesman for Indian Railways.
The two consecutive days of disruption are embarrassing for India, a nation growing in international stature and the third largest Asian economy.
The power companies said they were working to restore the power supply. It was not immediately clear whether the blackouts were partial or total in the different regions.
The grid failure on Monday struck in the early morning hours. Residents spent the rest of the night drenched in sweat amid humid weather, and many backup power systems had run out by daybreak. Power was partially restored after about six hours, authorities said.
That blackout left passengers stranded at train stations, and signal failures caused traffic snarls that choked the Indian capital's already congested roads during office hours.
Indians, however, have been no stranger to power cuts, which become more common during the summer when demand shoots up.
The Indian power minister, Sushilkumar Shinde, has already ordered an investigation into Monday's outage. He said the last time that an entire grid failed in north India was 10 years ago.
CNN's Jethro Mullen contributed to this report.