Army troops found a clandestine tunnel under construction in Tijuana, a border city in the northwestern state of Baja California, and arrested 17 people, Mexican media reported.
The tunnel is 10 meters (33 feet) deep and 370 meters (1,213 feet) long, but it does not come out on the U.S. side of the border, the Frontera newspaper said, citing police.
Authorities arrested 17 people who were building the tunnel, the newspaper said.
Soldiers spotted several suspicious individuals outside a warehouse, detained them and searched the building, discovering the entrance to the tunnel, the El Universal newspaper reported.
The tunnel has lighting and ventilation systems, a hydraulic lift and rails for the types of small motorized cars used in mines.
Several bales of marijuana, weighing a total of 15 kilos, were found in the tunnel, officials said.
The suspects and the marijuana were turned over to federal prosecutors, El Universal said.
Since the mid-1990s, authorities have discovered many clandestine tunnels along the border.
People traffickers and drug cartels often use clandestine tunnels to cross the vast U.S.-Mexican border, which runs 3,200 kilometers (1,988 miles). EFE