Cuba's national electric grid collapsed on Monday at midday, the country's grid operator said, leaving around 10 million people on the Caribbean island ​without power.

Grid operator UNE said it was investigating the cause ⁠of the nationwide blackout.

Cuba has for ​months suffered from hours-long, and more recently, ⁠days-long power outages linked in part to a decrepit grid and a U.S. imposed ‌oil blockade that has ​cut off the island's ‌fuel supply.

The nationwide outage is more ‌bad news for Cubans already exhausted from rolling blackouts that make it ⁠impossible for many to ‌work or ⁠sleep in the Caribbean summer heat.

Cuba ⁠has ⁠frequently struggled to keep the lights on during a ‌years-long economic crisis but the Communist-run government has entered unprecedented territory under increased ‌pressure from ​U.S. President ‌Donald Trump.

Nearly two-thirds of the country was already without power when ​the grid collapsed on Monday.