The bodies of 24 men have been found with their hands bound and shot to death execution-style outside the capital, authorities said Friday.
Assistant Mexico State Security Agency information director Antonio Ortega said authorities were at the scene.
The rural area just west of Mexico City has been marked by gangland slayings and land disputes between farming communities.
Mexico's drug cartels and criminal gangs have been slaying their rivals in increasingly large numbers and publicly dumping their corpses.
On Aug. 28, a dozen decapitated bodies were found outside Merida, the capital of Yucatan state.