The number of bodies found in the clandestine graves in La Barca, a city in the western Mexican state of Jalisco, has risen to 42, prosecutors said.
Federal prosecutors and personnel from the state prosecutors' offices in Jalisco and Michoacan have been digging since Nov. 9 at the site on the limits of the cities of Vista Hermosa and La Barca where the clandestine graves were discovered.
The clandestine graves are in the Tierra Caliente region, which straddles Michoacan, Guerrero and Mexico states.
The Caballeros Templarios and Cartel Jalisco Nueva Generacion gangs have been fighting for control of the Tierra Caliente region.
Two federal law enforcement agents disappeared in the region on Nov. 3 and a search led to the arrests of 22 local police officers and three civilians for their suspected connection to the case.
Rene Rojas Marquez and Gabriel Quijano Santiago, investigators with the federal Attorney General's Office, were ordered to join a federal operation targeting drug traffickers and run out of a joint operations base housing federal and state police and soldiers.
The AG's office investigators had orders to report to the base in Briseñas, a city located 120 kilometers (75 miles) from Zamora and near Michoacan's border with Jalisco.
Superiors lost contact with the investigators while the two men were traveling in an AG's office pick-up truck.
The burned truck was found in Cumuato, a community outside the city of Sahuayo, which is between Zamora and Briseñas.
Officials, however, have not said whether the missing agents' remains are among those found in the clandestine graves.
The bodies, including those of two women, were taken to the coroner's offices in Jalisco and Mexico City for DNA tests and identification.
Michoacan's forests and mountains are used by drug traffickers to grow marijuana and produce synthetic drugs. EFE