The An-32 cargo plane had arrived at Mit£, Colombia, carrying drums of fuel. After unloading the fuel there was a spill that was initially responded to by the crew. Airport firefighters approached to attend the event but were not allowed the use of foam or water due to electrical and electronic equipment that could be affected by the liquid. After starting the APU and engine no.2 for the flight back to Villavicencio, the crew felt an explosion and shut down the engines. Firefighters were unable to extinguish the rapidly developing fire. CAUSE (translated from original Spanish language report): Lack of adequate and effective procedures for fuel handling by the company and crew. Non-compliance by the crew of the aircraft, of the recommendations made by the Fire Fighting Service Airport and Control Tower.