From an army helicopter flying high above the Colombian countryside, a large black mark can be seen. It's oil, and it's spreading fast. An 800km long pipeline carrying oil for the United States has once again been blown up by left-wing rebels. The rebels say they oppose the exploitation of the country's oil by foreign multinationals. But it is oil that helps them fund their war; the mayor of nearby Aruaca claims that the rebels extort money from repair companies working to repair the pipeline they themselves blow up. Barranca, to the south, contains the country's biggest oil refinery. It should have brought riches to the people of Barranca, but instead it's brought fear and death.

A report by Saira Shah for Unreported World.

Produced by Mentorn