A dramatic plume of black smoke over Havana turned out to be a fire at the Ñico López oil refinery.
Cuban authorities say it was brought under control without injuries.
The blaze began in a warehouse near the refinery, and firefighters extinguished it before it spread to fuel storage or processing areas.
Officials have launched an investigation into the cause.
The blaze comes at a particularly fraught moment for Cuba’s energy system.
The island is already grappling with a deepening fuel crisis after key oil supplies from Venezuela were cut off by tightened US restrictions.
This followed the seizure of Venezuelan tankers and sanctions on fuel exports.
That blockade has squeezed Cuba’s ability to import crude and refined products needed to generate electricity and keep transport and services running.
The shortage has led to power outages affecting hospitals and infrastructure, rationing of fuel.
It has even led to a drop in aviation fuel that has forced some airlines to suspend flights.
Cuba Energy Strain
Mexican ships carrying humanitarian aid have recently arrived at Havana Bay to help ease the pressure.
But with no clear timeline for resuming regular fuel imports, the island’s energy system remains under strain.
United Nations experts have warned that the US oil restrictions are worsening humanitarian conditions for ordinary Cubans.
So while this fire was contained quickly, it highlights the fragility of Cuba’s refinery infrastructure.
It comes just as the country faces one of its toughest energy emergencies in decades.
