Twelve decapitated bodies bearing signs of torture have been discovered in eastern Mexico in an apparent gangland execution that has shocked the Yucatan Peninsula, a popular tourist destination.

Eleven headless male bodies were found piled on top of each other and covered with blankets yesterday in a suburb of the city of Merida, the capital of Yucatan state. Authorities said they were still looking for the heads.

Some of the cadavers had their legs bound, while one was stripped naked. Tattoos decorated the arms of some of the murdered men, most of which wore denim clothing.

Another decapitated corpse was discovered in a town called Buctzotz, 45 miles northeast of Merida.

The gruesome discoveries capped a day of violence across Mexico, which has seen a wave of drug and gang-related killings and kidnappings in recent months, claiming 2,700 lives already this year - more than for the whole of 2007.

Tomorrow, Mexicans will take to the streets in nationwide protests at the escalating violence, which has seen decapitated bodies littering southern and northern Mexico and kidnapping rates soar past those of Colombia and Iraq.

Merida, a city of 700,000 some 200 miles from the popular Caribbean resorts of Cancun and Playa del Carmen, has largely escaped the gang violence ravaging so many other Mexican cities.

Jose Guzman, a Yucatan state prosecutor, claimed that the executions were “an isolated incident and not part of a strategy to destabilize the state.”

But the regional press took a different view. Diario de Yucatan linked the murders directly to the “lengthening list of victims of the violence with which drug-trafficking cartels are fighting for control of the national territory.”

The murders were the first drug-related crime on such a scale in the state’s history, the paper said.

Just four drug-related murders had been reported in Yucatan state this year, according to El Universal newspaper.

Nearly two years ago, President Felipe Calderon launched a nationwide battle to take back territory controlled by some of the world’s most powerful drug gangs. The cartels have responded with unprecedented violence, especially along the US-Mexico border.

“There is ... an aspiration by organised crime to compete with the State for its basic powers,” Eduardo Medina Mora, the Mexican Attorney General, said this week. “This is why the president has led this effort to truly recover these regions for his citizens.”

However many ordinary Mexicans say police corruption is hindering the fight against drug violence, and hope tomorrow's demonstrations will force the government to act against it.

Decapitation and dismemberment have in recent years been adopted by drug trafficking gangs as the preferred method of revenge against rivals. Hitmen often leave notes on the bodies indicating it was a drug-related assassination.

In other violence, two shoot-outs in the Pacific coast state of Guerrero resulted in ten deaths, while the northern city of Chihuahua saw a further four killings.

Three other decapitated bodies had been found this week in an empty lot on the eastern outskirts of Tijuana, the crime-ridden border town favoured by young Americans in search of cheap booze, drugs and women.

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