Mexican cartels break open new front in drugs war

By Robin Emmott

DURANGO, Mexico (Reuters) - Drug gangs have forced open a bloody new front in Mexico's drugs war, extending their battles over smuggling routes into a formerly quiet northwestern state and further stretching the army.

A fight for control of the mountainous state of Durango has killed some 235 people this year, a jump in violence that poses a new challenge to troops already struggling to contain bloodshed along the U.S. border.

With only a few hundred soldiers in Durango, drug hitmen from eastern Mexico are taking over towns, kidnapping police, shooting up local government offices and slaughtering rivals.

It poses a fresh threat to President Felipe Calderon, who has staked his reputation on pushing back the cartels, and could fuel U.S. concerns that violence is overwhelming its southern neighbour.

The drug war has become the biggest challenge of Calderon's presidency and has started to spill over some parts of the U.S. border. Murders are rife in Mexican border cities like Ciudad Juarez, where Calderon sent 10,000 troops in March to tackle the gangs.

The outbreak of violence in Durango also marks a new challenge to top drug fugitive Joaquin "Shorty" Guzman on a formerly quiet patch of his home turf in northwestern Mexico.

Officials and analysts say Guzman, who has long been battling rivals in other parts of the country, is being attacked in Durango by the Gulf cartel and its brutal "Zetas" armed wing as they fan out from their base in northeastern Mexico, near Texas.

"We have a 600 percent increase in violence in Durango this year ... and we do not have the resources to attack these groups," the state's deputy attorney general, Noel Diaz, said in the state capital, also called Durango.