Energy company Union Electrica (UNE) stated that the power outage was caused by an unexpected accident at the Antonio Guiteras thermal power plant, located approximately 100 kilometers east of Havana.
"Repairs to the thermal power plant could take three to four days," publication wrote.
"Power was lost from Pinar del Rio in the far west to the central-eastern province of Camaguey."
Electricity was also cut in the eastern province of Las Tunas due to substation failures. The blackouts spared only the four far eastern provinces [Holguín, Granma, Santiago de Cuba, and Guantánamo - ed.].
Cuba faced severe power outages in recent years - even before the U.S. cut off oil supplies from the main provider, Venezuela, following the removal of dictator Nicolás Maduro from power in early January.
The Cuban government links the economic crisis to decades of U.S. economic sanctions, leading to a lack of investment in power generation and the electrical grid.
Reuters wrote that Havana residents, accustomed to periodic power cuts related to state rationing, largely reacted calmly to the new outages. Some traffic lights and businesses continued to operate thanks to solar panels or generators.
Fuel shortages forced the Cuban government to ration basic services, namely, garbage collection and transportation. Some Cubans have installed solar panels on their homes and vehicles to secure electricity amid rapidly rising fuel prices.
In late January, the U.S. president signed a decree allowing him to impose new tariffs on countries supplying oil to Cuba. Consequently, Mexico, an alternative supplier to Venezuela, announced that it will also halt oil deliveries to Cuba.
Trump also suggested that Cuba strike a deal with Washington "before it's too late," stating that the country will no longer be able to receive oil or money from Venezuela, which has been its key ally for decades.
In response, Cuban President Miguel Díaz-Canel highlighted that external pressure is unacceptable for his country, as Cuba remains a free and sovereign state upon which no one has the right to impose decisions.