HAVANA－A fire set off by lightning at an oil storage depot raged uncontrolled in the Cuban city of Matanzas, where four explosions and flames injured 121 people and left 17 firefighters missing. Cuban authorities said an unidentified body had been found late on Saturday.

The fire began during a thunderstorm on Friday night. Authorities said about 800 people were evacuated from the Dubrocq neighborhood closest to the fire.

The government said it had asked for help from international experts in friendly countries with experience in the oil sector.

Deputy Foreign Minister Carlos Fernandez de Cossio said the United States government had offered technical help to quell the blaze. He wrote in a tweet that the "proposal is in the hands of specialists for the due coordination".

Minutes later, President Miguel Diaz-Canel thanked Mexico, Venezuela, Russia, Nicaragua, Argentina and Chile for their offers of help. A support flight from Mexico arrived on Saturday night.

The official Cuban News Agency reported that lightning hit one tank, starting a fire, and the blaze later spread to a second tank. As military helicopters flew overhead dropping water on the blaze, dense columns of black smoke billowed from the depot and spread westward more than 100 kilometers toward Havana.

Roberto de la Torre, head of fire operations in Matanzas, said firefighters were spraying water on intact tanks trying to keep them cool in hopes of preventing the fire from spreading.

Cuba's Health Ministry reported that 121 people were injured, with five in critical condition. The Presidency of the Republic said the 17 people missing were "firefighters who were in the nearest area trying to prevent the spread".

Later on Saturday, the Health Ministry reported the body being found and said officials were trying to identify it.

There was no immediate comment on how much oil had burned or was in danger at the depot, which has eight giant tanks that hold oil used to fuel electricity generating plants.

"I was in the gym when I felt the first explosion," said Adiel Gonzalez, a local resident. "A column of smoke and terrible fire rose through the skies. The city has a strong smell of sulfur."

Many ambulances, police and fire engines were seen in the streets of Matanzas, a city with about 140,000 inhabitants that is on Matanzas Bay.

Local meteorologist Elier Pila showed satellite images of the area with a dense plume of black smoke moving from the point of the fire westward and reaching east to Havana.

Members of the Cuban Red Cross prepare to be transported to a place where firefighters were working to quell a blaze in Matazanas, Cuba, on Saturday. RAMON ESPINOSA/AP