A fire at a key fuel refinery in the capital comes amid Cuba’s mounting fuel emergency due to US-imposed restrictions.

A fire broke out at a key fuel processing plant in the Cuban capital Havana, threatening to exacerbate an energy crisis as the country struggles under an oil blockade imposed by the United States.

A large plume of smoke was seen rising above Havana Bay from the Nico Lopez refinery on Friday, drawing the attention of the capital’s residents before fading as fire crews fought to bring the situation under control.

Cuba’s Ministry of Energy and Mines said the fire, which erupted in a warehouse at the refinery, was eventually extinguished and that “the cause is under investigation”. There were no injuries and the fire did not spread to nearby areas, the ministry said in a post on social media.

“The workday at the Nico Lopez Refinery continues with complete normalcy,” the ministry said.

The location of the fire was close to where two oil tankers were moored in Havana’s harbour.

Cuba, which has been in a severe economic crisis for years, relied heavily on oil imports from Venezuela, which have been cut off since the abduction of the country’s leader Nicolas Maduro by United States forces last month.

US President Donald Trump has also threatened Cuba’s government and passed a recent executive order allowing for trade tariffs on any country that supplies oil to the island.

The country has seen widespread power outages due to the lack of fuel. Bus and train services have been cut, some hotels have closed, schools and universities have been restricted, and public sector workers are on a four-day work week. Staffing at hospitals was also cut back.

United Nations Secretary-General Antonio Guterres warned last week of a humanitarian “collapse” in Cuba if its energy needs go unmet.

On Thursday, two Mexican navy vessels carrying more than 800 tonnes of humanitarian aid arrived in Havana, underscoring the nation’s growing need for humanitarian assistance amid the tightening US stranglehold on fuel.

Experts in maritime transport tracking told the AFP news agency that no foreign fuel or oil tankers have arrived in Cuba in weeks.

Cuba can only produce about one-third of its total fuel requirements.

Cuba’s Deputy Foreign Minister Carlos de Cossio accused the US of carrying out “massive punishment” against the Cuban people in a post on social media Friday.

Cuba requires imports of fuel and “the US is applying threats [and] coercive measures against any country that provides it”, the deputy minister said.

“Lack of fuel harms transportation, medical services, schooling, energy, production of food, the standard of living,” he said.

“Massive punishment is a crime,” he added.

Mexico’s President Claudia Sheinbaum has said her government seeks to “open the doors for dialogue to develop” between Cuba and the US and has criticised Washington’s oil restrictions as “unfair”.