Firefighters and other specialists were still trying to quell the blaze at the Matanzas Supertanker Base, which began during a thunderstorm Friday night, the Ministry of Energy and Mines tweeted, the north American media have reported.
The official Cuban News Agency said the lightning strike set one tank on fire and the blaze later spread to a second tank.
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.
The Cuban authorities requested international assistance from friendly countries "that have the experience in the oil industry" to deal with the aftermath of the fire, the presidential office says.
Officials at Faustino Perez Hospital reported 52 injured, according to the provincial government's Facebook page. The hospital's director, Dr. Taymi Martinez, said one person was in extremely critical condition, three patients were in critical condition and 10 in serious conditions.
"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 sulphur."
KI/PR