HAVANA, Cuba (AFP) — Cuban authorities scrambled Sunday to restore power to the island after the second nationwide blackout in less than a week, as the grid struggles due to an aging infrastructure and a United States (US) oil blockade.

Some parts of Havana began to have power again, but others were still dark early Sunday, a day after the energy ministry reported a “total disconnection” of the national electric system in the country of nearly 10 million people.

A gas power station near Havana and another in the beach resort of Varadero were generating power again, as well as a hydroelectric plant in central Cuba, energy and mining minister Vicente de la O Levy said on X. A unit of a thermoelectric plant was also back online.

There have been seven nationwide blackouts since 2024, making life more difficult for Cubans who fear food will spoil in refrigerators, among other problems in a country in economic crisis.

The breakdowns have intensified since Cuba’s main regional ally and oil supplier, Venezuela’s socialist leader Nicolas Maduro, was captured in a US military operation in January.

US President Donald Trump has threatened to impose tariffs on countries that sell oil to Cuba.

No oil has been imported to the island since January 9, hitting the power sector while also forcing airlines to curtail flights to the island, a blow to the all-important tourism sector.

The latest blackout was due to an outage in a generating unit at one of the country’s eight thermoelectric plants, triggering a domino effect in the system, according to authorities.

The outages, as well as regular shortages of food, medicine and other basics, are spurring frustrations.

In a rare moment of violence, demonstrators vandalised a provincial office of the Cuban Communist Party last weekend.

The new blackout occurred as an international aid convoy began to arrive in Cuba this week, bringing sorely-needed medical supplies, food, water and solar panels to the Caribbean island.