discovery of a mass grave in northern Mexico, soldiers' originally unearthed 59 bodies in San Fernando in Tamaulipas state near Texas.

Since the discovery of a mass grave in northern Mexico, soldiers' originally unearthed 59 bodies in San Fernando in Tamaulipas state near Texas. The toll has now risen to 116, one of the worst slaughters in Mexico's ongoing war against the drug cartels. Mexico's attorney general is blaming the atrocity on the Zetas drug cartel.

 

 we can confirm the discovery of a total of 116 people killed in this criminal act ... by the Zetas," Marisela Morales, the attorney general, announced in Mexico City.

The body count could still rise. Mexican media reports that 128 corpses had now been recovered in San Fernando.

San Fernando is a town south of Brownsville, Texas on a well-travelled stretch of highway that runs near the Gulf Coast. It is an area regularly patrolled by the Mexican military.

Mexican Interior Secretary Francisco Blake Mora pledged to step up the presence of troops and federal police in the area. He says that officials will not leave the area until the killers and drug gang members there have been caught.

"Organized crime, in its desperation, resorts to committing atrocities that we can't and shouldn't tolerate as a government and as a society," Blake said.

More than 37,000 people have been killed since Mexican President Felipe Calderon sent in the army to fight the drug gangs in 2006, worrying the U.S. and some investors and tarnishing Mexico's international image as a favored tourist destination.

The victims in Tamaulipas are believed to have been killed after refusing to work for the Zetas, according to media reports. The gang is increasingly making a name for itself as the most violent of Mexico's powerful cartels.

Morales said 17 suspects had been arrested in the government's investigation, but she declined to give more details about any possible motives for the massacre or the identities of the victims.

The graves were near a ranch where 72 Central and South American migrants were killed last year by the Zetas preying on undocumented migrants heading north in search of work in the U.S.