Lights went out in all of Argentina and neighbouring Uruguay at around 7 a.m. (04:00 GMT) on Sunday, affecting around 50 million people. Utility companies in both countries blamed a technical malfunction. Cities in Brazil, Chile and Paraguay also experienced outages.
“As of 8:15 p.m. local time, 98 percent of power supply has been restored,” the Argentine Energy Ministry said in a statement.
Uruguay's UTE state power company said that 98.5 percent of power supply had been restored in the country.