HAVANA — Cuba's power grid collapsed nationwide on Saturday, leaving the island without electricity. The outage marked the third nationwide blackout in March and the second in the past week.

The total disconnection of the national energy system was caused by an unexpected shutdown of a generation unit at the Nuevitas thermoelectric plant in Camaguey province. The state-owned Cuban Electric Union reported a total blackout across the island without specifying a cause for the outage.

The last nationwide blackout occurred on Monday, and it took several days to restore power. Power outages have become relatively common in the last two years due to breakdowns in aging infrastructure. Daily blackouts of up to 12 hours are caused by fuel shortages, which also destabilize the power system.

On Sunday, Cuba began restoring its energy system following the nationwide power grid collapse. Early on Sunday, some 72,000 customers in Havana, including five hospitals, had electricity restored. Havana has a total population of approximately 2 million.

In Havana and in provinces including western Matanzas and eastern Holguin, local power microsystems were set up to supply the most vital centers. These microsystems prioritized essential services during the restoration process.

President Miguel Díaz-Canel said the island has not received oil from foreign suppliers for three months. Cuba produces barely 40% of the fuel it needs to power its economy. The government blames the outages on a U.S. energy blockade after U.S. President Donald Trump warned in January of tariffs on any country that sells or provides oil to Cuba.

The removal by the U.S. of Venezuela's former President Nicolás Maduro halted critical petroleum shipments from Venezuela to Cuba. These shipments had previously helped Cuba meet its energy needs.