Mexico ? Eleven people were found shot to death around Mexico on Saturday, some bearing signs of torture and left with threatening messages emblematic of drug violence.

Four of the victims were found in a car in the western city of Apatzingan, along with a message threatening the Zetas, a group of hit men for the Gulf drug cartel. The message was signed La Familia, a drug gang battling for territory in western Michoacan state.

La Familia was once considered aligned with the powerful Gulf cartel, but it was named as a separate gang in a government list of most-wanted drug trafficking suspects released last month.

President Felipe Calderon’s government has attributed fractures in the cartels to a military crackdown, saying the arrest of drug kingpins has set off internal battles for control that have led to Mexico’s sharp surge in drug-related violence.