The Revolutionary Armed Forces of Colombia (Farc) rebels were trying to retake a strategic mountain area near the Caribbean coast when they were hit.
Intelligence officials said the operation had been ordered by the Farc’s number two leader, Ivan Marquez, believed to be in Venezuela.
Colombia’s President Alvaro Uribe said the operation was a “message” to him.
Full Story: BBC News – Aerial attack kills 13 Farc rebels in Colombia