Mexico sends in reinforcements to stem drug wars on US border

Such efforts so far have failed to quell drug violence which has killed 28,000 people since President Felipe Calderon launched his war on drugs in late 2006.

The goal of Co-ordinated Operation North East was to reinforce government authority in the two states most heavily affected by a surge in violence as rivals fight for control of the multi-billion pound demand for drugs from the US across the 560-mile border.

The new effort also aims to keep the two cartels from regrouping after the takedown of key leaders. But in a media briefing with all government security officials and governors of Nuevo Leon and Tamaulipas, the affected states, provided no details or numbers of reinforcements and answered no questions.

Intense cartel violence has plagued the industrial city of Monterrey in Nuevo Leon and all of Tamaulipas, where cartel firefights and violence this month sent residents fleeing the once-picturesque tourist town of Ciudad Mier and where 72 migrants were found slaughtered.

Tamaulipas has some of the busiest border crossings in the world.

Governor Eugenio Hernandez said his state had been a major transport corridor for organised crime since prohibition, when the US outlawed alcohol in the 1920s into the early 30s.

"But the situation has recently become much more complicated," he said.

Recent government blows against the cartels included the killing earlier this month of Gulf cartel leader Antonio "Tony Tormenta" Cardenas Guillen and the 2008 capture of a founding member of the Zetas cartel, Jaime "the Hummer" Gonzalez Duran, who was sentenced for money laundering and weapons possession earlier this year.

The government already has similar operations in other parts of Mexico, including Chihuahua state where the border city of Ciudad Juarez across from El Paso, Texas, is considered one of the most violent cities in the world.

The splintering of other Mexican gangs has added to the bloodshed.

On Wednesday police said they captured the new leader of a drug gang formerly led by jailed Texan-born Edgar "La Barbie" Valdez Villarrea.

His capture triggered a battle for to seize control of the gang marked by decapitations, bodies hung from bridges and shootouts in the area stretching from Acapulco to Cuernavaca.

One faction kidnapped and killed 20 Mexican tourists in Acapulco, mistaking them for members of a rival cartel.