Millions of people in Cuba remained without power Saturday after a failure of the nation's electric grid left the island in the dark the previous night. The blackout is the fourth in the last six months as a severe economic crisis plagues the Caribbean country.

The collapse follows nationwide blackouts last year that plunged Cuba's frail power-generating system into disarray.

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.