U.S. authorities on Thursday said they found a sophisticated tunnel used to smuggle drugs between Mexico and San Diego, the second such discovery in the region in less than a month.
Federal authorities are asking San Diego warehouse owners near the Mexican border to help stop cross-border tunneling.
Representitives with the Federal Tunnel Task Force went door-to-door in Otay Mesa on Monday, handing out flyers. Officials want people to report noises and vibrations coming from under ground, or if they smell marijuana. The authorities also want warehouse owners to look out for renters who pay in cash or have unusual business hours.
The moves on Monday came in the wake of the discovery of two sophisticated drug smuggling tunnels. Both were found near the border in the last month.
The discoveries of the two tunnels netted nearly 50 tons of marijuana and renewed arguments for the legalization of pot by supporters of Proposition 19, which was struck down by California voters three weeks ago. Proponents of the measure want marijuana to be regulated and taxed to generate revenue for a cash-strapped state and plan to put it back on the ballot in 2012.
The tunnel found Thursday is more than seven football fields in length and extends from the kitchen of a home in Tijuana, Mexico, to two warehouses in San Diego's Otay Mesa industrial district. Investigators say this is one of the most sophisticated drug tunnels they've seen in years. The tunnel has a rail system, electricity and ventilation.
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.
"We think ultimately they are controlled by the same overall cartel but that the tunnels were being managed and run independently by different cells operating within the same organization," Unzueta said Friday.
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.
U.S. authorities do not know how long the latest tunnel was operating. Unzueta said investigators began to look into it in June on a tip that emerged from a large bust of marijuana, cocaine and methamphetamine by the San Bernardino County Sheriff's Department.
U.S. authorities followed a trailer from one of the warehouses to a Border Patrol checkpoint in Temecula, where they seized 27,600 pounds of marijuana. The driver, whose name was not released, was arrested, along with two others who went to a residence in suburban El Cajon that had $13,500 cash inside.
"That (trailer) was literally filled top to bottom, front to back," Unzueta said. "There wasn't any room for anything else in that tractor-trailer but air.
"Three tons of marijuana were found in a "subterranean room" and elsewhere in the tunnel on the U.S. side, authorities said.
Mexican officials seized four tons of pot at a ranch in northern Mexico, bringing the total haul to more than 20 tons.