Cuba has suffered a massive power outage affecting Havana and the country’s provinces that has left millions in the dark.

The lights were out across all of Havana's waterfront skyline, a Reuters witness observed, with only a scattered few tourist hotels operating on fuel-fired generators. Reports on social media from outlying provinces both east and west of the capital city suggested much of the country of 10 million people was without power.

Cuba's national electrical grid failed late on Friday, according to state-run media, leading to widespread blackouts in the capital Havana and across the country. Officials said they were investigating the causes and magnitude of the grid failure,