Colombian rebels bombed an oil pipeline and paralyzed 80,000 barrels per day of crude transport but exports from Latin America's No. 4 oil producer were not affected, the state energy company Ecopetrol said on Sunday.
It was the third attack on the 780-kilometre Cano Limon-Covenas line blamed on leftist rebels since late February. The rebels commonly target infrastructure in their decades-long conflict with the government.
The pipeline, the second longest in the country, transports crude oil from the Arauca department on the Colombian-Venezuelan border to the port of Covenas.
"The attack caused an oil spill into a river and we had to suspend pumping," an Ecopetrol source told Reuters.
Exports and production were not immediately affected, he said. The state-oil company has sufficient reserves to maintain programmed shipments, although the source could not say when pumping would begin again at the pipeline. A prolonged stoppage could eventually hit exports.
The army said the Revolutionary Armed Forces of Colombia, or FARC, planted the bomb, which exploded on Saturday in the Norte de Santander department.
Latin America's longest running insurgency is at its weakest moment in decades after the deaths of top commanders and a string of desertions. But the guerrillas still attack oil and gas pipelines in remote areas and briefly kidnapped nearly two dozen oil contractors earlier this year.
There were 31 rebel attacks on pipelines last year, according to Ministry of Defense statistics.
A U.S.-backed government crackdown on illegal armed groups has greatly reduced violence in Colombia, encouraging an investment boom especially in the energy and mining industries.
Strong growth prospects for the economy helped the South American country regain investment-grade status this year from the ratings agency Standard & Poor's and is hoping Moody's and Fitch will soon follow suit.