Mexico ? Police have found the bodies of five men dumped in a landfill near the Mexican resort city of Acapulco.

The Guerrero state Public Safety Department says the men had been shot to death and police officers found a note with the bodies signed “The boss of bosses.”

A statement issued Saturday by the department says investigators also found at least 50 bullet casings and duct tape at the scene. There was no immediate information on a motive for the slayings, but the Pacific resort city has long been plagued by drug violence.

More than 13,500 people have died in drug-related violence throughout Mexico since the government launched an offensive against cartels in December 2006.