BOGOTA, Colombia (AP) -- Suspected Marxist rebels on a motorcycle assassinated the mayor of a small town outside his home in southwest Colombia, police said Tuesday.

Luis Humberto Trujillo, the three-term mayor of the agricultural town of Rivera, some 160 miles (260 kilometers) southwest of the capital, was shot 10 times Monday night by two masked assailants, said Col. Oscar Torres, police commander in the Huila province.

No arrests have been made.

Police said Colombia's largest rebel group, the Revolutionary Armed Forces of Colombia, or FARC, was likely behind the attack, but said right-wing militia groups also operate in the region.

In 2002, the FARC declared all mayors and town council members to be military targets, leading many to flee their towns -- but not Trujillo.

"Despite this general threat from the FARC, [Trujillo] always rejected any type of protection the National Police offered," Torres said.

Trujillo was well-liked by townspeople, a local politician said.

"He was a tranquil man, self-assured. ... He believed he had the unanimous backing of the town and that this provided his main security," Carlos Augusto Rojas, a provincial congressman, told local radio.

More than 30 mayors and 60 town council members have been assassinated in the past three years, according to the Colombian Federation of Municipalities.

Colombia's leftist rebels have been battling the government for 40 years, and the conflict claims some 3,500 lives a year.

Copyright 2004 The Associated Press.