Cuba’s power grid collapsed Friday night, triggering a nationwide power outage and plunging its more than 10 million people into darkness.

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.

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