People walk on a darkened street Thursday during a power outage in Caracas, Venezuela. (Carlos Garcia Rawlins/Reuters)

Most of Venezuela was without power Thursday and Friday as the country, already grappling with a political and humanitarian crisis, faced another dangerous threat: a near-total power outage.

Schools, offices and shops shut down, and doctors and nurses struggled to keep hospitals running, with generators in short supply. President Nicolás Maduro blamed Washington for the blackout, saying on Twitter, “The electricity war declared and directed by the imperialist United States against our people will be overcome!”

Maduro is facing growing calls to step down as a number of countries, including the United States, have recognized opposition leader Juan Guaidó as interim president.

The power outage sparked fear at hospitals in the capital, where the lack of generators meant health workers were left to work in the dark with limited equipment and choose specific areas to provide with electricity. On Friday, the University Hospital of Caracas had electricity in only a few areas, including the emergency room and the neonatal ward, thanks to generators.

“Last night was crazy,” José Luis Mesa, a 49-year-old electrician whose infant grandchild was being treated in the emergency room, told The Washington Post. “We saw how the security guards ran all over the place to get diesel.”

These photos capture the mood in Venezuela at night throughout the lengthy blackout.

Residents cross a street Thursday during the power outage in Caracas, Venezuela. The power failure left much of Venezuela in the dark early Thursday evening in what appeared to be one of the largest blackouts yet in a country where power outages are increasingly common. Crowds of commuters in the capital city were walking home after metro service ground to a halt and traffic snarled as motorists struggled to navigate intersections where traffic lights were out. (Eduardo Verdugo/AP)

Mothers and relatives wait Thursday outside an intensive-care unit for infants at a clinic in Caracas. (Ariana Cubillos/AP)

People walk in the dark Friday during the outage in Caracas. (Rayner Pena/EPA-EFE/REX/Shutterstock)

People cross a street Thursday during the power outage in Caracas. The Venezuelan government denounced "sabotage" against the country's main electric power dam after a massive blackout left Caracas and vast regions of Venezuela in the dark. (Yuri Cortez/AFP/Getty Images)

People sit in a shopping center Friday during the blackout in Caracas. (Ivan Alvarado/Reuters)

Lighting their way with candles, relatives of a patient walk in the darkened hall of a clinic Thursday in Caracas. (Ariana Cubillos/AP)

Journalists use their smartphones Thursday in Caracas. (Matias Delacroix/AFP/Getty Images)

Travelers wait Friday at Simón Bolívar International Airport in Maiquetia, Venezuela. (Yuri Cortez/AFP/Getty Images)

The Metropolitano stadium sits all but empty Thursday before the suspension of the Copa Libertadores match between Venezuela's Deportivo Lara and Ecuador's Emelec in Barquisimeto, Venezuela. (Ronaldo Schemidt/AFP/Getty Images)

Zuñiga reported from Caracas and O’Grady from Washington.

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