Authorities in the southern Mexico state of Chiapas say they have confiscated 1,639 coca plants.

The state attorney general's office says the discovery in Tuxtla Chico near the Guatemalan border came from an anonymous tip that led to a warrant.

The plants found in a more than 13,000-square-foot plot were tested by experts and confirmed to be the type used to extract the key ingredient for making cocaine, according to a statement issued Tuesday by the Chiapas state prosecutor's office.

Chiapas is a mountainous state bordering Guatemala known for coffee-growing. Cultivation of coca plants is highly unusual outside of South America's Andean region.

The operation was carried out by state authorities with the help of Mexico's new Federal Police prevention unit and the army and marines.