Millions in Cuba were left without power on Friday as the country was plunged into yet another major blackout.

The country’s entire electricity grid suffered “total disconnection” that triggered a nationwide outage, Cuba’s energy ministry said.

Power was restored to some priority areas by late evening, including those near hospitals and water pumping stations in the capital Havana, grid operator UNE said.

It is at least the sixth partial or total blackout to hit Cuba this year, where ageing electricity infrastructure and chronic fuel shortages have been placed under further strain by a US blockade on oil shipments to the communist-run nation.

UNE said the outage started just before 14:00 local time on Friday (18:00 GMT) due to a transmission fault coupled with poor weather conditions in central Cuba.

Protocols to begin the “gradual restoration” of power were activated, the operator’s national load dispatch director Felix Estrada said, with the process ongoing on Saturday.

Cuba relies heavily on fuel imports, meaning tight US sanctions and an oil blockade since the start of the year have exacerbated existing shortages.

Food and medicine have also become more scarce, with hospitals struggling to function normally and schools and government offices having to close.

“Lately, it’s becoming a habit,” Havana resident Frank Lorenzo told news agency Reuters on Friday.

“Before it happened less frequently – once a month… just yesterday we were 24 hours without electricity, they turned it on for just an hour and it went down again.”

“It’s one thing after another: no water, no gas for cooking, no electricity,” 36-year-old schoolteacher Lidia Fernandez told news agency AFP. “Honestly, I don’t know how we haven’t gone crazy.”

Francisco Rodriguez, 78, said his home had already gone without power for 28 hours on Friday and feared he would not have light “for several days”.

The repeated blackouts have prompted rare protests in Cuba, where unauthorised demonstrations are illegal and those who defy the ban risk being jailed.

Havana has blamed its fuel crisis on the Trump administration and denounced all of its sanctions – including a new round announced in August – which are part of a wider pressure campaign against the Caribbean island’s leadership.

Cuba’s regional ally Venezuela was believed to have sent it around 35,000 barrels of oil a day – about half of its oil needs – until Venezuela’s own supplies were cut off following the US seizure of its President Nicolás Maduro in January.

US President Donald Trump has threatened tariffs on countries shipping oil to Havana, and a number of such shipments have been seized by the US.

Washington meanwhile attributes Cuba’s energy crisis to poor internal management and has accused it of posing a “national security threat”. Trump has openly discussed toppling its leadership, including threatening a “friendly takeover” in March this year.