Four Colombian police officers and a civilian were killed when a bomb exploded today in the same city where guerrillas tried to assassinate the mayor with a car bomb two days earlier, authorities said.
Police found the explosives in a duct at the radio station in Neiva where rebels had tried to kill Mayor Cielo Gonzalez on Thursday but the bomb exploded as they were moving it, Defense Minister Juan Manuel Santos said.
"We are not sure why it exploded. Everything points to an accident," Santos told local radio.
Four bomb disposal experts were killed in the car and a female bystander died, police said.
Gonzalez, who has been threatened by the Revolutionary Armed Forces of Colombia, or FARC, escaped Thursday's attack when a bodyguard had the suspicious vehicle towed away. Ten people were wounded when it exploded shortly afterwards.
Rebel attacks are less common since President Alvaro Uribe began a US-financed offensive to combat FARC and the cocaine trade that the rebels use to sustain Latin America's oldest guerrilla war. But FARC remains a potent force in rural areas.
Neiva, 180 miles (250 km) south of Bogota, and surrounding areas are a corridor for drug traffic from neighboring provinces that have been the focus of US-funded operations. FARC's Teofilo Forero command, one of its more experienced fronts, is active in the area.