The official Cuban News Agency said the lightning strike set one tank on fire and the blaze later spread to a second tank.
The Facebook page of the provincial government of Matanzas said the number of injured had reached 77, while 17 people were missing. The Presidency of the Republic said the 17 were “firefighters who were in the nearest area trying to prevent the spread.”
The accident comes as Cuba struggles with fuel shortages. There was no immediate word on how much oil had burned or was in danger at the tank farm, which stores oil used to fuel electricity production.
“I was in the gym when I felt the first explosion. A column of smoke and terrible fire rose through the skies,” resident Adiel Gonzalez told The Associated Press by phone. “The city has a strong smell of sulfur.”
Authorities said the Dubrocq neighborhood closest to the fire was evacuated, while Gonzalez added that some people decided to leave the Versailles district, which is a little farther from the tank farm.
There were many ambulances, police and fire engines, he said.
Matanzas, which has about 140,000 inhabitants, is 100 kilometers (62 miles) from Havana, on Matnzas Bay.
Cuban President Miguel Diaz-Canel traveled to the area of the fire early Saturday, officials said.
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.
“That plume can be close to 150 kilometers long,” Pila wrote on his Twitter account.
Andrea Rodríguez on Twitter: www.twitter.com/ARodriguezAP