Police found three severed heads in plastic bags in the Pacific coast resort city of Acapulco, authorities said Monday.
The black bags were discovered outside a tunnel that connects central Acapulco to the outskirts of the city, the Guerrero state Public Safety Department said in a statement. The victims were male.
A note left at the scene said the beheadings were revenge for the killing of a man who was shot dead during an attempted kidnapping.
Meanwhile, police announced the capture of a suspected prominent drug gang member who allegedly oversaw kidnappings, extortion, bribery and local drug distribution for a group known as the "independent cartel of Acapulco."
The federal Public Safety Department said in a statement that Benjamin Flores Reyes, alias "The Godfather," was arrested Sunday after a half-year investigation.
It added that he studied criminal psychology for a time during 15 years he spent living in the United States. He returned to Mexico about three years ago and allegedly signed up with the organization formerly led by Edgar Valdez Villarreal, known as "La Barbie," who was arrested last year.
In recent months, Acapulco has seen a wave of organized crime violence blamed on warring drug gangs.
On Sunday, armed men attacked a police station in the city, wounding an officer. The same suspects later shot at a house, wounding two people at the residence.
More than 35,000 people have been killed nationwide in drug-related violence since President Felipe Calderon launched a military offensive against cartels shortly after taking office in December 2006.