Dhaka (AFP) - An inquiry was under way Sunday into Bangladesh's nationwide blackout, which plunged homes, businesses and even the prime minister's office into darkness.
Power was restored across the country by Sunday morning, a government minister said.
"There is no power shortfall anywhere in the country. The supply is now fully normal across the country," junior power minister Nasrul Hamid told reporters after the outage which hit just before midday on Saturday.
"We've set up a probe committee to investigate. The committee has already started work and will submit its findings in three days."
Loud cheers could be heard in Dhaka late Saturday as the lights came back on in phases, after residents spent hours outdoors or on their roofs.
Dhaka, with a population of 15 million, had resembled a ghost town as dusk descended, with homes, businesses and government offices plunged into darkness, and hospitals and the international airport forced to use backup generators.
Water supplies were hit as most of the pumps which supply groundwater could not function.
Speaking to the Dhaka Tribune, Chowdhury Alamgir Hossain, a director of state-run Power Grid Company of Bangladesh, blamed the failure of a transmission line from India for the blackout.
All cities and towns linked to the national grid had been hit, Masud Alberuni, a senior power ministry official, told AFP.
Alberuni said the grid "tripped" and "all the power-generating stations in the country automatically shut down in a cascading effect".
The outage marked the first time the entire country has been without power since November 2007 when Bangladesh was hit by a devastating cyclone.
The country's garment and other industries were largely unaffected because many of the thousands of factories were closed on Saturday.
Electricity supplies in Bangladesh, one of the world's poorest countries with a population of 155 million, are vastly overstretched at the best of times.
Bangladesh, like many developing countries, has an expanding middle-class and increasing industrialisation which is imposing heavier loads on limited generating capacity.
To boost supply, Dhaka began importing power from India late last year through a line stretching from India's eastern state of West Bengal to southwestern Bangladesh.
But India itself struggles to produce enough power, with a major blackout in 2012 hitting two-thirds of its states.
In Bangladesh, the presidential palace, the prime minister's office, government offices and television stations were among premises hit by the outage.
But many people in poor rural parts of the country, accustomed to regular power cuts lasting many hours, did not even know that the blackout was nationwide.