43 Die in battle between police, gunmen in western Mexico

One of those killed was a police officer, according to the source in Tinaja de Vargas, near the town of Tanhuato.

A preliminary police report leaked to Efe also put the death toll at 43, but said that all of the fatalities were gunmen.

Bodies were left strewn on the ground in the vicinity of the El Sol ranch, located on a dirt road about 3 kilometers from a toll plaza on the Occidente Mexico-Morelia-Guadalajara highway.

Michoacan Gov. Salvador Jara said he would not comment until his administration has a clearer idea of what happened, though he mentioned that the shootout apparently began when federal officers tried to pull over a suspicious vehicle.

The leaked police report said the gunmen were in possession of 42 assault rifles, a rocket-launcher and a heavy-caliber Barrett rifle.

Sources in the Michoacan state Attorney General's Office told Efe the confrontation occurred as federal police tried to arrest crime bosses Adrian Alonso Guerrero Covarrubias and Heraclio Guerrero Martinez.

The men, whose organization is involved in drug trafficking, kidnapping and protection rackets, are accused of ordering last week's assassination of mayoral candidate Enrique Hernandez Salcedo in Yurecuaro, Michoacan.

The Guerrero family outfit is also suspected in the March 2014 slaying of Tanhuato Mayor Gustavo Garibay Garcia, a crime originally attributed to Hernandez Salcedo in his then-capacity as the leader of a vigilante group.

Hernandez Salcedo led one of the armed militias that arose in Michoacan in early 2013 to defend their communities from the Caballeros Templarios, a drug cartel with sidelines in kidnapping, extortion and armed robbery.

He and 19 members of his militia were arrested for the Garibay murder, but the charges were subsequently thrown out due to lack of evidence and Hernandez Salcedo accused federal authorities of having attempted to frame him.