A fault at a transformer station on the outskirts of Havana has caused "a significant production loss in western Cuba" and thereby "a failure in the national power system", announced the Cuban energy department shortly after 8 pm on Friday evening, local time.
The power outage has left the capital's streets in darkness. The internet is also affected by the outage, which has hit large parts of the country – including the provinces of Guantánamo, Artemisa, Santiago de Cuba, and Santa Clara.
Cubans are not unfamiliar with long power outages. Friday's outage is the fourth in five months. The outages have previously led the country's government to declare a state of emergency and close schools and public institutions to reduce consumption.