Argentina’s main energy company said Sunday it was “slowly beginning to restore” electricity after a massive power failure left large swathes of the South American country and neighboring Uruguay in the dark.
It was unclear how many people had been affected by the blackout, but the nations have a combined population of more than 45 million.
Edesur said on Twitter that power had been returned to 34,000 customers as of Sunday morning.
“The return of electricity generation to the interconnected system of the Federal Capital and Greater Buenos Aires has begun,” it said. It noted the process would take several hours.
Uruguayan energy company UTE tweeted that the system was being reinstated from scratch.
“There are already coastal cities with service and work continues toward general restoration,” it said.
It said the blackout was due to a “flaw in the Argentine network” which left the entire country and several regions of Uruguay without electricity.
Argentina’s energy secretary said that the blackout occurred around 7 a.m. local time, when a key interconnection system collapsed. It said the causes “are being investigated and are not yet determined.”
The blackout affected the entire Argentine capital of Buenos Aires, in addition to provinces in the north and south.
Since taking office, Argentina’s President Mauricio Macri has said that gradual austerity measures were needed to revive the country’s struggling economy. He has cut red tape and tried to reduce the government’s budget deficit by ordering job cuts and cutting utility subsidies.