"The national electrical system has been subject to multiple cyberattacks," Maduro wrote on Twitter on Sunday.
CARACAS - Venezuelans woke up to a fourth day of an unprecedented nationwide blackout on Sunday, leaving residents concerned about the impacts of the lack of electricity on the South American country's health, communications and transport systems.
Socialist President Nicolas Maduro - who is facing a challenge to his rule by the leader of the opposition-led congress, Juan Guaido - has blamed the blackout on an act of "sabotage" by the United States at the Guri hydroelectric dam, but experts say it is the outcome of years of underinvestment.
"The national electrical system has been subject to multiple cyberattacks," Maduro wrote on Twitter on Sunday. "However, we are making huge efforts to restore stable and definitive supply in the coming hours."
Guaido invoked the constitution to assume an interim presidency in January, arguing that Maduro's 2018 re-election was fraudulent. He has been recognized as Venezuela's legitimate leader by the United States and most Western countries.
Despite pressure from frequent opposition marches and US sanctions on the country's vital oil sector, Maduro is not open to negotiations on ending the political impasse and seems intent on trying to stay put, said Elliott Abrams, the Trump administration's envoy for Venezuela.
The blackout, which began Thursday afternoon, increased frustration among Venezuelans already suffering widespread food and medicine shortages, as the once-prosperous OPEC nation's economy suffers a hyperinflationary collapse. Food rotted in refrigerators, people walked for miles to work with the Caracas subway down, and relatives abroad anxiously waited for updates from family members with telephone and internet signals intermittent.
"What can you do without electricity?" said Leonel Gutierrez, a 47-year-old systems technician, as he carried his six-month-old daughter on his way to buy groceries. "The food we have has gone bad."