Mexico City-- Eleven decapitated bodies showing signs of torture have been discovered on Mexico's Yucatan peninsula near the city of Merida, authorities said.

The discovery is another indication of widening drug violence in Mexico, the Los Angeles Times reported Friday. A 12th decapitated body was found about 120 miles south of Merida, Yucatan state authorities said. Merida is a gateway for tourists traveling to the Maya ruins at Chichen Itza, the newspaper said.

Decapitation has become a favorite tactic of warring drug gangs that have contended for control over smuggling routes.

Authorities in Tijuana said four decapitated bodies were found there this week, apparent casualties of a violent struggle for control of drug smuggling from Mexico into San Diego, the Times said.

The bodies found Thursday in Yucatan were wearing handcuffs, El Universal reported.

Drug violence has escalated in Mexico since President Felipe Calderon began a crackdown on drug trafficking. More than 2,500 people have died in drug-related violence this year, the Times said, citing unofficial counts by Mexican media.