A massive power outage across Chile plunged the country¡¯s capital Santiago into darkness on Tuesday and knocked out electricity to major copper mines in the country¡¯s north, buffeting global metal markets.

Hours after the outage began and as darkness fell, Chile¡¯s government announced a state of emergency and established a curfew from 10 p.m. to 6 a.m. (0100 to 0900 GMT) from the northern region of Arica to the southern region of Los Lagos.

The widespread blackout was caused by a transmission line failure in the country¡¯s north, Interior Minister Carolina Toha said, ruling out a cyber attack as a cause.