Cuba's capital Havana plunged into darkness for a second night on Saturday as efforts to restore power proceeded in fits and starts, with setbacks slowing progress and leaving several million still without electricity across the island.

Pockets of Cuba's capital Havana saw the lights flicker back on though vast areas of the city and country continued without electricity on Sunday morning, after a nationwide grid collapse that knocked out power to 10 million people.

Cuba suffered a massive power outage Friday night affecting Havana and the country's provinces that left millions in the dark. Cuba's Ministry of Energy and Mines said at around 8:15 p.m. local time an outage at the Diezmero substation on the outskirts of Havana had caused "a significant loss of generation in western Cuba and,