MEXICO CITY, April 13, 2011 (AFP) - The United States has called them Mexico's most dangerous crime syndicate. President Felipe Calderon has likened them to Al-Qaeda.
Mexico's ruthless "Los Zetas" drug cartel engaged in assassinations, kidnappings, extortion and organized crime, now is accused of its second mass killing in eight months after 116 people turned up in mass graves.
Their name comes from the word "zeta" -- Spanish for the letter z -- a code term used by top army commanders.
Founded by deserters from the Mexican special forces and thought to have many corrupt former officials and ex-police on its payroll, the group is responsible for a growing amount of the narcotics trade and organized crime in Mexico.
The group also is said to have trained the Michoacan based "La Familia" cartel, a smaller operation but one which is employing similar ruthless tactics, including numerous executions.
The former elite army counter-narcotics commandos who make up its ranks once served as hit men for the Gulf Cartel in northern Mexico, but broke away in a bloody turf war, and began to carry out its own trafficking operations.
What makes the Zetas especially fearsome is the special paramilitary training they received while fighting the country's drug mafia, which they now use with great success against the very police and military operatives who trained them.
Some of the Zetas are even said to have received training at the US-based School of the Americas, a renowned paramilitary academy where some of Latin America's most feared despots were schooled.
Los Zetas' most important Mexican drug-trafficking strongholds are the lucrative border states of Tamaulipas and Nuevo Leon. But it has extended its tentacles relentlessly southward and now is a force to be reckoned with across Central and South America.
The group was among the early crime syndicates in Mexico to employ heavy weaponry and full-scale military tactics, reportedly amassing an arsenal that has included 50 caliber machine guns, grenade launchers and even ground-to-air missiles.
Their hallmark is the bloodcurdling ruthlessness with which they carry out their operations in the five year old drug war, including the massacre in Tamaulipas last year of 72 migrants from Central and South America.
Los Zetas now have been fingered in the brutal slayings of 116 people found this week in a mass grave.
Los Zetas is said to be led by a former Mexican special forces soldier named Heriberto Lazcano, or "El Lazca."
Lazcano is wanted in the United States and Mexico for multiple murders and drug trafficking. The Mexican government meanwhile has put a two million dollar bounty on his head.
Over the years, the gang has diversified its operations into migrant-smuggling, selling pirated goods, kidnapping and extortion, and also now operates across much of southern Mexico, even as it continues to wage its bitter turf war with its former Gulf Cartel employers for control of lucrative smuggling routes into the United States.
As they expand their operations alarm in rising among Mexico's neighbors, including Guatemala, which is seeing an increase in the number of drug trafficking operations attributed to Los Zetas.
The group is reported to be trying to bolster its presence in its southern neighbor by stepping up recruitment from among the ranks of Guatemala's special forces.
The government of Guatemala has tracked the group's southward march with alarm, and tried to fight back.
President Alvaro Colom last month declared a state of siege and ordered an army to crack down against the group's operations in a remote section of the border with Mexico where drug smugglers have used clandestine air strips to move drugs.