Mexico City ? In a sign of the spreading violence in Mexico, 11 decapitated bodies were found late Thursday near the colonial city of Merida on the Yucatan peninsula, officials said.

The bodies bore signs of torture, and some were unclothed. Yucatan state officials said a 12th decapitated body was found later about 120 miles south of Merida, a city that is often used as a gateway for tourists on their way to the famed Mayan ruins at Chichen Itza.

Warring drug gangs have routinely decapitated rivals during the past two years as they battle for coveted routes for smuggling drugs north into the United States.

Four decapitated bodies were found in Tijuana earlier this week in killings that appeared tied to fighting among traffickers over control of the corridor into San Diego.

But headless bodies have also turned up in other corners of Mexico as violence has spread beyond traditional battlegrounds along the U.S. border.

The Web site of the El Universal newspaper said the bodies found in Yucatan were handcuffed and showed signs that they were beaten. The Reuters news service, citing unnamed police sources, reported that the bodies had tattoos of star signs and the letter “Z.”