Cuban state media outlet Cubadebate said the blackout was caused by a fault at the Antonio Guiteras thermoelectric plant, located about 100km (62 miles) east of Havana, which cut electricity from Pinar del Rio in the far west of the country to the eastern Las Tunas province. In all, two-thirds of the country, including Havana, were left without power, according to the national electric company UNE, which said it was working to restore services.