A deadly fire that has consumed at least half of a large oil facility in western Cuba and threatened to worsen the island’s energy crisis has been largely controlled after nearly five days, authorities said.

Flames that recently consumed the fourth tank in the eight-tank facility in Matanzas were almost quelled, although the third tank remains on fire and surrounded by smoke, according to an unidentified Cuban firefighter.

“We can’t go in for now,” he told Cubavision, a government TV channel.

The blaze killed at least one person and injured 128 others, with 14 firefighters missing.

It also forced officials to evacuate more than 4,900 people and shut down a key thermoelectric plant after it ran out of water, raising concerns about a new round of blackouts in addition to the ones the government announced last week for Havana.

Cuban President Miguel Diaz-Canel cautiously celebrated the work by local firefighters and special teams that Mexico and Venezuela sent that employed boats, planes and helicopters to fight the blaze whose billowing, toxic smoke could be seen from the capital of Havana.

“(Tuesday) was a victory day, but we cannot be overconfident,” he tweeted on Wednesday.

The fire at the Matanzas Supertanker Base began on Friday after lightning struck the key infrastructure, which operates an oil pipeline that receives Cuban crude oil that powers thermoelectric plants.

It also serves as the unloading and transshipment centre for imported crude oil, fuel oil and diesel.

The government has not provided an estimate of damages or said how much it has lost overall in key fuel supplies.

The first tank was at 50% capacity and contained nearly 25,000 cubic metres of fuel.

The second tank was full.