Updated

Mexican authorities say gunmen shot and killed the mayor of a town in the western state of Michoacan, the latest in a string of attacks against elected local officials.

Michoacan state prosecutor Adrian Lopez says Vista Hermosa Mayor Octavio Carrillo was arriving at his home when four gunmen waiting for him opened fire.

Carrillo is the sixth elected local official killed in Michoacan since June.

Violence has soared in Michoacan, President Felipe Calderon's home state, as drug gangs battle each other for territory and intensify attacks on police.

Calderon says drug violence claimed at least 6,000 lives last year.