A ranch in this municipality less than 100 kilometers (60 miles) from the U.S. border served as a hideout and training facility for the brutal Los Zetas drug cartel, Mexican authorities said.

The soldiers surrounding the Las Aguilas property allowed Efe to walk around the spread that was home to some 200 Zetas gunmen.

The ranch's main house has expensive furniture, game rooms and stags' heads mounted on the walls, though almost everything that was not nailed down is now gone.

Until a few weeks ago, Las Aguilas was Los Zetas' biggest training camp as well as a hideout for cartel members operating here in Nuevo Leon and in the neighboring state of Tamaulipas, military sources told Efe.

Troops shut down the base last week after a series of clashes that left 21 Zetas dead and a dozen others in custody

The Zetas first began showing up at the ranch around six months ago, according to Vallecillo residents who spoke on condition of anonymity.

The gunmen gradually took over an extensive swath of semi-desert dotted with the abandoned homes and ranches of people who emigrated to the United States.

Vallecillo is one of several rural municipalities in northern Nuevo Leon that have seen their populations decline.

Authorities became aware of the Zetas' presence at Las Aguilas after an Oct. 11 incident in which armed men traveling in a score of SUVs fatally shot two federal police officers who were patrolling the Monterrey-Laredo highway.

That attack prompted the deployment of hundreds of federal cops, soldiers and marines, backed by helicopters, to hunt down the aggressors.

The search led eventually to Las Aguilas.

Despite a siege involving four helicopters and hundreds of personnel on the ground, around 150 Zetas managed to escape before the security forces could take the ranch.

Federal and state police have assumed responsibility for public safety in Vallecillo, whose municipal police department recently shrank from 11 officers to just two.

Most of the town's barely 2,000 residents remain holed up in their houses, fearing that the Zetas will return to exact revenge for the loss of the base.