About 120 firefighters were working to put out the blaze and had quickly extinguished one of the tanks, Ramirez said. Another tank was still in flames, sending up black smoke on Thursday morning.
"This fire is controlled," Ramirez said on television at the refinery, where the tank was in flames behind him. "We're putting it out."
An investigation into the cause will be conducted, but all indications are that it was sparked by a strong electrical storm, Ramirez said.
"We suppose a lightning bolt hit one of our tanks and the fire broke out," he said.
The refinery produces fuel for the domestic market. But the blaze won't lead to any shortages of fuel in the country, said Asdrubal Chavez, vice president of refining for the state oil company Petroleos de Venezuela SA.
A much larger fire was sparked by a powerful blast last month at the Amuay refinery that killed at least 42 people, the country's worst-ever refinery disaster. The causes of that accident are under investigation.
Written by Associated Press