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 restored power to most of Havana after a nationwide outage affected 10 million people. The grid collapse was triggered by a shorted transmission line. Oil-fired plants are back online, yet Cuba faces ongoing energy issues due to outdated infrastructure and geopolitical tensions.

Cubans have grown resigned to frequent outages -- including blackouts ranging anywhere from four hours to 20 hours or more.