Rowdy teacher protests in southern Mexico have caused delays and bottlenecks in transporting fuel from the country's top refinery in Salina Cruz, and state oil giant Pemex is on alert for new roadblocks, a company official said on Wednesday.
Blockades on Tuesday caused long lines of tanker trucks unable to transport fuels for hours.
Late last week, Pemex warned that road blockades by protesters could cause the facility's storage tanks to reach their limits and potentially force the company to shut the refinery, Pemex's biggest with a capacity to process 330,000 barrels of crude per day.
"There's a problem with our storage capacity," the Pemex official said, asking not to be named because of company policy. He said the transport of waste and refined products had only been temporarily affected so far.
A key highway used by the refinery to transport nearly all of the gasoline and diesel it produces has been specifically targeted in the past week by one of the most combative factions of Mexico's CNTE teachers union, a tactic often used to apply pressure and exact concessions from the government.
"This is a serious problem," the Pemex official said.
On Tuesday morning, members of CNTE's Section 22 in Oaxaca, fierce opponents of a 3-year-old government education reform, successfully cut off access to a highway known as the Carretera Transistmica, forcing dozens of tanker trucks to idle for hours.
A stretch of the smaller, coastal highway 200 also was blocked, although both blockades were later dismantled.
These and other roadways also were temporarily shut down last week before police were able to clear them of protesters in deadly clashes that marked some of the worst CNTE-related violence in months.