The Mexican army discovered a smuggling tunnel on the border of California and Mexico.
The tunnel entrance was located inside a water purification plant, about 300 feet south of a metal fence separating Mexico from the United States.
The tunnel was located 39 feet below ground and 131 feet in length. It was also equipped with ventilation and electrical systems.
Seven people were taken into custody by the army during the operation and soldiers confiscated a small amount of marijuana.
The Associated Press contributed to this report.