Power has almost all been restored to millions of homes after a "massive" blackout which affected the whole of Argentina and Uruguay.

Edusur, a major provider to the two nations, confirmed the outage in a tweet on Sunday morning and engineers had been working around the clock to restore power.

Argentinian website Infobae said Edusar had said "the blackout is at a country level and also affects Uruguay", adding that nothing like this had ever happened.

Apagon en gran parte de Mar del Plata pic.twitter.com/PzoZ0keOSC — Cris Ge (@CrisGe9) June 16, 2019

Image: Downtown Buenos Aires during the power cut

The outage is understood to have happened at 7am local time, about 12pm GMT, and affected millions of people.

By evening, electricity had returned to 98% of Argentina, according to state news agency Telam.


Power had also been restored to most of Uruguay's three million people.

Image: A woman prepares formula milk by candlelight

Image: A butcher and greengrocer in Buenos Aires with no electricity

Argentina's power grid is generally known for being in a state of disrepair, with substations and cables insufficiently upgraded as power rates remained largely frozen for years.

The country's energy secretary Gustavo Lopetegui said the blackout occurred when a key Argentinian inter-connection system collapsed.

Image: Public transport was also affected

Image: Traffic lights were off Argentina after the power cut

Edesur said on Twitter that the failure originated at an electricity transmission point between the power stations at the country's Yacyret dam and Salto Grande in the country's northeast.

But why it occurred was still unknown.

Informamos la normalización del servicio a 450.000 clientes a las 11:53 am. Nuestro Centro de Control prioriza el abastecimiento a hospitales y centros de salud del área de concesión. https://t.co/XrqalOLIv7 pic.twitter.com/176LKI3rR5 — Edesur Argentina (@OficialEdesur) June 16, 2019

Silvio Ubermann, who lives in Buenos Aires, said: "If this had been a weekday, it would've been chaos. Sometimes there is not light in the summertime as a result of high electricity consumption, but never such a large blackout in the whole country.

"I've never seen something like this."

People reported blackouts in several regions. One twitter user shared an image of the darkened Mar del Plata.

Image: The blackout covered all of Argentina and Uruguay

It also impacted regional elections taking place in several parts of Argentina.

#EDProvincia Según informa el Poder Judicial el inicio de los comicios se retrasó por el corte de luz. Pero no se suspende. Afirman que las elecciones iniciarían ni bien haya luz solar.#ApagónSanLuis #Apagón #ApagónMasivo #SinLuz pic.twitter.com/e2YxUc2LP1 — El Diario de la República (@ElDiariodelaRep) June 16, 2019

Images on local media showed some people casting their votes while others hold their mobile phones above them to cast light on the ballot paper.

There were reports that some places opened later for voting because of the power outage.