Mexico City  - Mexican army troops shut down what they called one of the world's largest and most modern illicit drug factories, a plant that covered an immense piece of property in a remote area of the state of Durango, media reports said Saturday.

The plant, which encompassed 22 different buildings on 240 hectares, was used to produce methamphetamine, the chemically- produced drug also known as crystal, and to process marijuana.

The buildings were spread out over the acreage and covered with camouflage to escape discovery from the air, the newspaper reported.

Eyewitnesses described the layout as a huge enterprise or factory. Every building had its own power source. The finished drugs were stored in a warehouse. A special building housed the liquid chemicals used in production.

The Defence Ministry said troops went looking for the factory near the Sinaloa region based on descriptions given investigators. The army found 18 vehicles, weapons and military uniforms at the lab.

Mexican President Felipe Calderon engaged the army in the drug fight in 2006 when he came into office, to short-circuit the corrupt relations between the drug cartels and local police and officials.

Mexico has become the main corridor for transit of cocaine and manufacture of other drugs delivered to the hungry US drug market. More than 9,000 people have been killed in the infighting of the cartels since January 2008. (dpa)