SAN DIEGO (CBS/AP) Investigators suspect a major drug cartel was the driving force behind two long, sophisticated tunnels connecting Mexico with the U.S. that were discovered this month along with more than 40 tons of marijuana.
Authorities said an underground passage located Thursday was similar to one found earlier - both spanning about 2,000 feet from Mexico to San Diego and equipped with lighting, ventilation, and a rail system for drugs to be carried on a small cart.
The tunnels are believed to be the work of Mexico's Sinaloa cartel, headed by that country's most-wanted drug lord, Joaquin "El Chapo" Guzman, said Mike Unzueta, head of investigations at U.S. Immigration and Customs Enforcement in San Diego.
The tunnel found Thursday is more than seven football fields long and extends from the kitchen of a home in Tijuana, Mexico, to two warehouses in San Diego's Otay Mesa industrial district.
Three men were arrested in the United States, and the Mexican military raided a ranch in Mexico and made five arrests in connection with the tunnel, authorities said.
U.S. authorities have discovered more than 125 clandestine tunnels along the Mexican border since the early 1990s, though many were crude and incomplete.
The tunnel found Thursday is one of the most sophisticated to date, with an entry shaft in Mexico lined with cinderblocks and the rail system, Unzueta said.