(Bloomberg) -- Venezuela’s fuel crisis is poised to deteriorate even further after one of its biggest refineries was halted over the weekend following a nearby oil spill.

Petroleos de Venezuela SA’s El Palito refinery stopped producing gasoline after its fluid catalytic cracker was shut due to a malfunctioning valve, said union leader Ivan Freites. The refinery was producing about 20,000 barrels-a-day of the fuel when it was shut, he said. The crude and vacuum distillation units were also stopped, according to a person familiar with operations.

The OPEC nation is already rationing fuel after the country’s biggest refineries suffered multiple breakdowns in recent weeks amid sweeping U.S. government sanctions that ban the sale of gasoline to the country.

Restart efforts at the 140,000-barrel-a-day refinery are being complicated by an oil spill that happened Sunday near the facility, according to Freites. Heavy rains caused a ditch of crude and byproducts to spill over and reach the sea. The oil spill near El Palito is the second in recent weeks to befoul Venezuela’s Caribbean coast.

Last month, crude began washing up on beaches in the Morrocoy national park, a popular tourist destination known for its pristine beaches and wildlife. The spill covers an area of about 8 kilometers (5 miles), said said Eduardo Klein, a marine ecologist at the Simon Bolivar University in Caracas. “This is the worst oil spill in 24 years,” he said.

Environmental minister Oswaldo Barbera said almost 6 kilometers of the spill have been cleaned in a Twitter post from Aug. 10. The source of the spill is still being investigated. A spokesperson for PDVSA declined to comment.

©2020 Bloomberg L.P.