Mexico City, Feb 11 (Inditop.com/EFE) The heads of four people were found in Mexico, but the bodies have not yet been recovered, officials said.

Three of the heads were found in the northwestern state of Sinaloa and the fourth turned up in the southern state of Guerrero.

Three of the heads were found Tuesday at 7 a.m. in front of a restaurant and a school in Palmillas, a town in Sinaloa, said a spokesman for the state attorney general’s Office.

The victims were three unidentified young men, the AG’s office spokesman said.

The killers only left behind the heads, shocking the town, a Palmillas police department spokesman told EFE.

“Lately, we’ve seen these kinds of things,” the police spokesman said.

A message, whose contents have not been disclosed, was left with the heads, indicating that the killings were likely linked to Mexico’s drug cartels.

Police in Ciudad Altamirano, a city in Guerrero, said a human head was found inside a cooler on Lazaro Cardenas boulevard, which links the city with Coyuca de Catalan.

The head belonged to a man “with a dark complexion, whose hair was shaved off and his facial skin removed, and a piece of cardboard with a message was left”, the Guerrero Public Safety Secretariat said.

The body has not yet been recovered and authorities have not released the contents of the message.

The head of Cesareo Pineda, police chief in the town of Petatlan, was found Sunday, a day after he was kidnapped.

The police chief’s head was left inside a plastic cooler in front of the house of former Petatlan mayor and Regional Ranchers Union of Guerrero State, or UGREG, leader Rogaciano Alva.

Alva is wanted for the killings of 17 ranchers in clashes in the towns of Iguala and Petatlan in 2008.

Mexico has been plagued in recent years by drug-related violence blamed on powerful cartels that are battling for turf and control of the smuggling routes into the US.