Some of the world's largest copper mines in Chile have resumed operations after experiencing a disruption due to a major power outage.

The outage, resulting from a transmission line failure in northern Chile, occurred mid-afternoon on Tuesday and affected the country's power grid from the mining-intensive north to the central and southern regions, reported Reuters, citing sources close to the matter.

BHP’s Escondida copper mine was left without electricity, according to a source close to the matter.

State-owned copper miner Codelco reported that all its mines were affected, with the Chuquicamata, Andina, Salvador and El Teniente mines losing power and others operating partially on backup generators.

Antofagasta and Anglo American also confirmed their mines were using generators to maintain operations.

Chile's National Electricity Coordinator (CEN) reported that more than 90% of residential consumption had been restored by Wednesday morning, although some cities still experienced intermittent power.

Escondida returned to full activity, while Anglo American's Los Bronces and El Soldado mines, along with its Chagres smelter in central Chile, had power restored after the outage.

Codelco announced a gradual return to normalcy across all its divisions, and Antofagasta confirmed the resumption of its operations.

Interior Minister Carolina Toha expressed concern at a press conference, highlighting the failure of several safety nets and the repeated issues faced by other power stations attempting to restart.

The outage was linked to ISA Interchile, an energy distributor subsidiary of Colombia's ISA owned by state oil company Ecopetrol.

ISA Interchile's general manager, Luis Llano, stated that the company was investigating the cause of the outage and noted malfunctions in electronic and software protection systems that led to the high-voltage line disconnection and subsequent grid shutdown.