CAIRO: A huge power outage blacked out most of Cairo Thursday causing major disruption across the city of some 20 million people at the height of the morning rush hour.
Services were completely suspended on one of the city's three metro lines and heavily disrupted on a second, the state MENA news agency reported.
Power was gradually restored several hours later as temperatures rose towards 40 degrees Celsius in the middle of the day.
"Most of the power has been restored, the metro is working and so are water and sanitation plants," Energy Ministry spokesman Mohammad al-Yamani told AFP.
The government was investigating the disruption, which had left parts of the capital without running water, he added.
The outage also hit telecommunications, knocking out 2,000 cell phone signal boosters, said a statement by Vodafone Egypt, the country's top provider.
As consumers switch on fans and air conditioning units across the vast metropolis, supply routinely fails to meet demand in summer, forcing authorities to impose rolling power cuts neighborhood by neighborhood.
But Thursday morning's outage was the most extensive in years, as investment in generation has failed to keep up with rising population numbers amid the economic woes plaguing the country since the Arab Spring of 2011.