A bomb caused a fire on a section of Colombia's Trasandino oil pipeline late on Wednesday, state-run oil company Ecopetrol said, the fourth attack on the pipeline this year.
The bombing took place in western Narino province, near the border with Ecuador, the company said in a statement.
The pipeline was not pumping at the time of the attack and the company was working to control the fire, it said.
There have been more than a dozen attacks on Colombian pipelines so far in 2019. The 485-mile (780-km) Cano Limon pipeline was kept offline for most of last year because of more than 80 bombings.
Although Ecopetrol did not name the group responsible, the leftist National Liberation Army (ELN) rebels, considered a terrorist organization by the United States and the European Union, regularly attack oil infrastructure.