WATCH: Venezuelans on edge over power outage paralyzing the country

CARACAS, Venezuela — Opposition leader Juan Guaido said Sunday he will ask Venezuela's legislature to declare a "state of alarm," authorizing the delivery of international aid in response to a catastrophic power outage that has paralyzed the country.

At least 15 patients with advanced kidney disease were reported to have died since the blackout began on Thursday, as hospitals struggled to provide emergency services and the threat of spoiling food supplies put many on edge.

"We must attend to this catastrophe immediately. We cannot turn away from it," said Guaido, the 35-year-old leader of the National Assembly who in January declared himself interim president, triggering a power struggle in the oil-rich country of 30 million.

He told reporters he is convening an emergency session of the National Assembly for Monday to declare a "state of alarm" and authorize the delivery of international aid.

Such an action would set up another test of wills with President Nicolas Maduro, who last month used the military to repel an opposition bid to bring in humanitarian supplies from Colombia and Brazil.

But Maduro vowed on Sunday he would not back down. "This macabre strategy to bring us to a confrontation will fail," he wrote on Twitter.

The Venezuelan health ministry also denied that the blackout had caused any deaths in public hospitals as reported.

But the government announced that schools and workplaces would remain closed Monday as the power outages continued.

Military stance 

Guaido meanwhile called for more street protests Monday to pressure Maduro to step down.

"You have the right to go into the street, to protest, to demand, because this regime is letting Venezuelans die," he said, appealing to the armed forces "to stop covering for the dictator."

Guaido is recognized by more than 50 countries as Venezuela's acting president, which have backed his calls for new polls, but the military high command has so far stood by Maduro despite a plummeting economy and deep discontent.

In Washington, National Security Advisor John Bolton suggested members of the military were reconsidering their support for Maduro.

"There are countless conversations going on between members of the National Assembly and members of the military in Venezuela, talking about what might come, how they might move to support the opposition," Bolton said in an interview on ABC's "This Week." 

One reason the security forces have refrained from arresting Guaido, he said, "is Maduro fears if he gave that order, it would not be obeyed."

Electromagnetic attack? 

Maduro blames "imperialism" for the country's accumulating woes, and claims the power outage was caused by an electromagnetic attack on the Guri hydroelectric complex, which supplies 80 percent of Venezuela's electricity.

Guaido dismissed that explanation as "Hollywoodesque." Critics blame the government for failing to maintain the power grid, as did the Lima Group, a primarily Latin American bloc.

For ordinary Venezuelans, the blackout has piled misery upon an already agonizing day-to-day struggle to survive in a once prosperous country now reeling from hyperinflation and economic collapse.

"Every day is worse," said Edward Cazano, a 20-year-old who lives with his mother and three brothers in a poor Caracas neighborhood called Pinto Salinas. "We have the worst services in the world: no light, no water, sometimes no gas."

Hospitals with back-up generators were using them for emergency services, leaving patients to cope in the dark.

"This has been horrible. Everything dark. Only some areas are operating with a generator," said Sol Dos Santos, a 22-year-old whose daughter is hospitalized.

Some isolated cases of looting were also reported in Caracas on Sunday.

Dialysis patients at risk 

No national data was available about the impact of the power outage, but an NGO said at least 15 patients with advanced kidney disease died after they stopped receiving dialysis treatments in darkened hospitals. 

Francisco Valencia, director of the Codevida health rights group, said some 10,200 people were at risk because dialysis units had switched off.

Businesses remained shut, and public transport barely functioned.

"I am very nervous because this situation isn't being resolved. The little food we have in the refrigerator is going to spoil. How long are we going to endure this?" asked Francisca Rojas, a 62-year-old retiree in Caracas.

The blackout has been one of the worst and longest in recent memory in Venezuela, which is already suffering from serious shortages of food and medicine due to the overarching economic crisis.