Chilean authorities said they restored power to most homes on Wednesday, hours after a massive, rare blackout caused transport chaos in the capital and forced the president to declare a state of emergency and curfew across much of the country.

Chile's worst blackout in well over a decade struck on Tuesday afternoon, leaving millions without power.

President Gabriel Boric blamed private companies that manage the grid for the system's failure.

"This is outrageous! The daily life of millions of Chileans can't be impacted like this by companies that don't do their job," Boric said in a statement issued by his office.

Early Wednesday, "90 percent of (electricity) consumption was restored" to homes, the power system's operator said in a statement.

According to the Senapred disaster response agency, the outage affected an area stretching all the way from Arica in the long, narrow South American country's north to Los Lagos in the south, an area home to over 90% of Chile's 20 million people.

The blackout disrupted transport in the capital Santiago, where thousands were evacuated from the metro and people jostled to board overflowing buses.

President Boric had activated "a state of emergency due to a catastrophe" and announced a curfew until 6 a..m. Wednesday.

Attack ruled out

Interior Minister Carolina Toha ruled out sabotage as the reason for the power loss, which began at 3:16 p.m .in the middle of the southern hemisphere summer.

"There is no reason to assume that this is an attack," she said on Tuesday, telling reporters it was more likely "a failure in the system's operation."

The metro company, which transports 2.3 million passengers every day, said workers were deployed to all stations "to support safe evacuations."

Out-of-service traffic lights caused major gridlock, with some people having to walk for hours under the hot sun to reach their homes.

Shops and offices closed early.

"They let us leave work because of the power cut, but now I don't know how we will get home because all the buses are full," worker Maria Angelica Roman told AFP in Santiago.

"At the bank where I work, all operations had to stop," 25-year-old clerk Jonathan Macalupu said.

Dramatic rescues

The Chilevision broadcaster showed video of people trapped on a mechanical ride several meters high at an amusement park in Santiago before being rescued.

An AFP photographer saw firefighters rescue a distraught elderly woman, who had been trapped inside an elevator.

The country's hospital system and prisons were operating on emergency generators.

Boric flew over the capital by helicopter to assess the situation.

In the coastal city of Valparaiso, witnesses also reported shops and businesses closing early and traffic chaos.

Chile boasts one of the best power networks in South America and has not had a blackout this big in about 15 years.

In 2010, damage to a power plant in southern Chile plunged hundreds of thousands of people into darkness for several hours.

That outage happened a month after a massive 8.8-magnitude earthquake killed more than 500 people and rocked the national power grid.