A pipeline supplying Venezuela's huge Amuay-Cardon refinery in Paraguana region was damaged by an explosion and fire caused by sabotage, Interior Minister Jesse Chacon told reporters on Sunday.
"This explosion was an assault on the Venezuelan people," Chacon said. "There was an explosion below the pipeline in three places, one that fractured the pipeline causing a spill that has been controlled, and another two that caused cracks," Chacon said.
Energy Minister Rafael Ramirez said earlier on Sunday that the incident, which occurred just hours before Venezuelans were to vote in parliamentary elections, did not affect fuel supplies and that the situation was under control.
Authorities were opening an investigation to determine the cause of the incident, he told state television. "There is enough crude at the refinery so there should be no problems with fuel supplies," he said.
ABN State news agency reported the incident was on Line 1 Ule-Amuay pipeline, which carries 150,000 barrels per day (bpd), in El Guanabano in Zulia State. Line 2, carrying 250,000 bpd, was also affected by the fire due to high temperatures, it reported.
State oil company PDVSA refinery chief Alejandro Granado would not comment on the incident when contacted by Reuters.
PDVSA blamed sabotage for a small gas and crude leak in October at another oil well in Zulia State. Zulia, where the country's Lake Maracaibo oil hub is located, is one of the few states held by an opposition governor.
Left-wing President Hugo Chavez has in the past blamed falling production in Venezuela on sabotage by his opponents although some critics say the output problems were more likely due to lack of investment in wells.
Venezuela's oil industry was battered by an opposition-led strike in late 2002 and early 2003. Analysts say output never recovered to pre-strike levels although the government says production is normal at more than 3 million bpd.