The U.S. Drug Enforcement Administration says Mexican authorities discovered an incomplete tunnel that extends into San Diego and is equipped with a lift system, ventilation and lighting.

The DEA said Wednesday that the tunnel runs nearly 1,000 feet from its entry in Tijuana, Mexico, including 860 feet into the United States. There is no exit on the U.S. side.

The DEA says Mexican authorities arrested more than a dozen people inside the tunnel Wednesday. No arrests have been made in the United States.

The tunnel reaches a depth of 90 to 100 feet and is believed to have been under construction for about two years.