Police found the heads of an active duty officer and a former law enforcement agent in a cooler Tuesday near Ahome, a city in the northwestern Mexican state of Sinaloa, officials said.
The victims have been identified as Ubaldo Cervantes Juarez, a 39-year-old former agent of the defunct Federal Investigation Agency, or AFI, and Luis Alonso Ruiz Felix, a 46-year-old state police officer, the Sinaloa Attorney General's Office said.
Gunmen had kidnapped the two men on Monday, the AG's office said.
A message from a gang claiming credit for the killings was found with the bodies, but officials did not reveal the contents.
AG's office personnel transported the bodies to a funeral home.
inaloa is home to the powerful drug cartel led by Joaquin "El Chapo" (Shorty) Guzman.
The Sinaloa cartel, sometimes referred to by officials as the Pacific cartel, is the oldest drug cartel in Mexico and Guzman, considered extremely violent, is one of the most-wanted criminals in Mexico and the United States, where the Drug Enforcement Administration has offered a reward of $5 million for him.
The rival Los Zetas cartel has been trying to grab control of some areas in the state from the Sinaloa organization, which is also battling the Beltran Leyva organization.
The war on drugs launched by former President Felipe Calderon, who was in office from 2006 to 2012, left about 70,000 people dead, or an average of 32 per day, in Mexico, officials say.
Calderon, of the conservative National Action Party, or PAN, deployed thousands of soldiers and Federal Police officers across the country to fight drug cartels. EFE