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.