The explosion, occurring at 3.15 AM near the town of Uribia, caused 40 of the train’s 12o wagons to derail. Traffic on the railroad has stopped until the train’s been removed and the tracks repaired. Until then the mine won’t be able to transport coal for exportation.Authorities blamed the assault on the Revolutionary Armed Forces of Colombia or FARC guerrillas, who earlier this month knocked out a major oil pipeline with a bomb. Cerrejon, one of Colombia’s two largest coal miners, produced 30 million tonnes of coal last year and hopes to expand to 38 million to 40 million tonnes by around 2015. Rebel attacks on oil pipelines, energy towers and other infrastructure have dropped sharply under President Álvaro Uribe, who has used billions of dollars in U.S. aid to drive back the rebels. But they are still a capable force in remoter parts of the country.