The bodies of eight people, with their throats slit, were found inside a vehicle in the violence-hit southern Mexican state of Oaxaca, said officials.
Local authorities said a threatening message was also found at the crime scene.
The bodies of the men, aged 17-20, were found on the afternoon of Friday, 27 November, inside a gray SUV with a Mexico City licence plate in Cosolapa, a rural municipality in Oaxaca.
A message was found alongside the victims with a threat directed at the Los Zetas drug cartel.
Agents with Mexico's Attorney General's Office arrived at the scene to remove the bodies of the slain people, believed to have been residents of a highland area of the neighbouring state of Veracruz.
