The bodies of Victor Enrique Payan and another officer were found with a note attached to them warning others not to join the Sinaloa drug gang in northern Mexico, El Universal reported Thursday.

Numerous Mexican police officers have been implicated in drug cartels despite recent efforts by the Mexican government to crack down on the gangs.

The head of Mexico's federal police force was killed this month by a group of gunmen, police officials said. Edgar Millan Gomez was shot several times outside his Mexico City apartment building.

Mexican President Felipe Calderon has sent Mexican police to several border towns in recent months to combat the growing violence associated with drug trafficking.