Egypt's president has blaming widespread power cuts in recent days on years of lack of investment, while warning people were trying to cripple his government's efforts to rebuild the country.

In a TV address on Saturday, Abdel Fattah el-Sisi said that the power cuts were "the most significant incident over the last three decades", adding that the country needs to invest at least $12bn over the next five years to generate sufficient amount of electricity for its population.     

"This is a battle for our existence," Sisi said in the special address to the nation, three months into his presidency. "We need to carry out a huge power generation development."   

"We should be aware that such a crisis cannot be remedied overnight," the president added. "We as Egyptians are facing huge insurmountable obstacles and no one, the president nor the government, will be able to overcome them individually without your support."

On Thursday, a huge power cut hit most of Cairo causing major disruption across the capital 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.

Power was gradually restored several hours later as temperatures rose towards 40C in the middle of the day.

The power disruption also left parts of the capital without running water, and hit telecommunications, knocking out 2,000 mobile phone signal boosters.

The energy shortages has forced authorities to impose rolling power cuts neighbourhood by neighbourhood.

Thursday's power cuts were 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.

Source: Al Jazeera and agencies