Up to 10 million Chileans were affected in a 1,300km radius by the blackout, whose cause is still to be found [Reuters]

A power blackout that paralysed large areas of Chile into total darkness has cast doubt on the reliability of the South American country's electricity grid.

Engineers were able to fully restore power generation and get distribution up to 90 per cent of normal, the government said on Saturday after the blackout, which lasted a couple of hours in most places.

Around 10 million people were left without electricity, and thousands in the capital, Santiago, had to be evacuated from trains and the underground transport system.

Rodrigo Alvarez, the Chilean energy minister, said the cause of the blackout had not been determined but he cited problems in two power lines and a failure in a computer system.

"We are trying to solve this problem as soon as possible because, in addition to the supply failure, we had a serious failure in the remote recovery system," Alvarez said, noting that such an incident had "never happened before".

The blackout acutely exposed the fragility of the energy grid in the world's biggest copper producer, which was devastated by a powerful earthquake in 2010.

Critics have blamed their president, Sebastian Pinera, for underinvestment in infrastructure and his popularity ratings have dropped since taking office last year.

Prior to the power failure, he was already struggling with massive protests by university students demanding deep educational reforms.

Copper mines were also affected: the mining company, Angloamerican, said its Los Bronces mine was halted while the state-run Codelco said its Andina division and El Teniente mine had halted.

But Codelco later said power had been restored at the Andina division and El Teniente. It said output was not hurt at Andina as generators were used.

Source: Al Jazeera