A massive power breakdown has hit India for a second day running, leaving more than half the country without power.
Officials said the northern and eastern grids had both collapsed. All Delhi metro services have been halted and staff are trying to evacuate trains.
Monday's power failure caused severe disruption and travel chaos across northern India.
It was unclear why the grid collapsed but the power minister said some states may have been taking too much power.
Sushil Kumar Shinde said power would be restored in "another 90 minutes".
After Monday's cut, engineers managed to restore electricity to the northern grid by the evening, but at 01:05pm on Tuesday, it collapsed again.
The eastern grid failed around the same time, officials said.