Cuba's national electricity grid collapsed late on Sunday, the state-owned national electric utility said, plunging the island of about 10 million people into darkness as blackouts are becoming ever more frequent.
The Union Electrica de Cuba did not provide any further details in its posts on social media websites X and Facebook on Sunday night.
The outage follows three nationwide blackouts in July and comes as a US-imposed oil blockade has crippled the island's already aging energy infrastructure.
Pressure on the power system has mounted as Cuba struggles to secure fuel imports.
It lost a key source of fuel after an oil blockade imposed by US President Donald Trump, following Washington's January 3 ouster of Venezuelan President Nicolas Maduro.
Venezuela had long been Cuba's primary oil supplier, with imports from Mexico also halted amid increased US pressure.
The power crisis coincides with a cautious opening of Cuba's tightly controlled energy sector, driven by fuel shortages and severe US sanctions.
Havana recently authorised its first foreign-backed fuel import venture and allowed nearly 200 Cuban businesses to participate in wholesale fuel distribution.
