The bodies of 11 people were found in Mexico state, which surrounds the Federal District and forms part of the Mexico City metropolitan area, officials said.
Five of the bodies were found Monday in Toluca, the state capital, and the other six in the city of Zinacantepec, the Mexico state Attorney General's Office said.
The victims in Zinacantepec "were found inside an automobile," the AG's office said in a statement.
The vehicle containing the bodies was abandoned in the city's Barrio de La Veracruz section and had Federal District tags, the AG's office said.
All of the unidentified victims were men and a message from the La Familia Michoacana drug cartel was left with the bodies, media reports said.
Five other bodies were discovered in the Cedros de Toluca district of the state capital.
The Valley of Mexico was rocked by violence last weekend, with 22 people murdered in Mexico City alone, officials said. EFE