FARC guerrillas attacked the Caño Limon-Coveñas oil pipeline, Colombia's largest, halting its operation early on Sunday morning and causing a crude oil spill that affected three towns in Arauca province, on the border with Venezuela.

Colombia's state-owned oil company Ecopetrol, which operates the pipeline along with Occidental de Colombia, OXY, announced in a communique that due to the attack they had shut down the Arauca and Arauquita aqueducts, two of the points affected along with Saravena.

Ecopetrol and OXY asked the public "to abstain from using water from La Blanquita creek, which is a tributary of the Arauca River."

Local authorities said that the Revolutionary Armed Forces of Colombia, or FARC, rebels attacked the pipeline with explosives about 3:30 a.m. (0830 GMT) at Km. 107, in the municipality of Cubara in Boyaca province. The Royota River, which runs near the site, flows into the Arauca River and toward Venezuela.

The attack comes in addition to many other FARC strikes, as well as attacks by the National Liberation Army rebels, on the Caño Limon-Coveñas pipeline since it began operating in 1986.

The pipeline transports some 80,000 barrels of crude produced in the Caño Limon field in Arauca to the port of Coveñas on the Caribbean Sea, from where it is exported.

Mines and Energy Minister Mauricio Cardenas told RCN La Radio that "since very early in the morning workers were setting up barriers (to contain the spill) ... such that the waters (of the rivers and streams) are not continuing to be contaminated."

"The issue is, above all, to ensure that the pipelines can return to operation and that the public can reestablish water service so that this very basic and essential service is not affected," he added.

The spill in eastern Colombia comes a few hours after another spill affected Putumayo province in the southwest, where the FARC staged three attacks on the Transandino pipeline and other facilities.

Ecopetrol reported that the attacks caused a crude spill into La Dorada creek.

Another environmental emergency was registered in Barrancabermeja, a port on the Magdalena River where Ecopetrol has established an industrial complex, but this situation was apparently caused by criminals who installed an illegal valve on the Vasquez-Galan pipeline to siphon off oil, resulting in another spill.

This spill affected the La Cira, Juan Esteban and Caño Arenales swamps and reportedly has placed the local ecosystem at great risk. EFE