BOGOTA (Reuters) - Leftist guerrillas in northeastern Colombia killed two contractors working on a pipeline for the state oil company, Ecopetrol, military sources said on Monday.
The shooting occurred on Sunday in the rural municipality of Teorama along the border with Venezuela, while the workers were doing maintenance work on the Cano Limon-Covenas pipeline.
"A sniper from the National Liberation Army (ELN) shot from the houses on the other side of the Catatumbo River," General Fernando Montoya, the commander of a special forces unit which operates in the area, told reporters.
Ecopetrol condemned the attack in Norte de Santander department in a statement and urged authorities to investigate the killings.
The ELN and a larger rebel group, the Revolutionary Armed Forces of Colombia, or FARC, have recently raised the tempo of attacks on oil infrastructure to demonstrate their continued military capabilities.
The attacks, including assaults on the Cano Limon-Covenas pipeline, have lowered oil production to under a million barrels per day over the last few months, below the government's goal of a million barrels a day.
Though the two rebel groups, considered terrorists by the United States and the European Union, have been weakened by a U.S.-backed military offensive, their attacks often close down pipelines for days at a time.
The Colombian government has been in peace negotiations with the FARC for nearly two years, in an effort to end a five-decade-long conflict which has left over 200,000 dead and millions displaced.
In May, President Juan Manuel Santos announced that the government had also held preliminary talks with the ELN, which opposes oil exploration on the grounds that it damages the environment and exploits local populations.
(Reporting by Luis Jaime Acosta; Writing by Julia Symmes Cobb; Editing by Jonathan Oatis)