Mexican troops stand guard at a "major cross-border drug tunnel" running from Mexico to California.<br/> The tunnel links warehouses in an industrial park south of San Diego, and the Mexican border city of Tijuana.<br/> Measuring around 370 metres, the tunnel has structural supports, electricity, and ventilation.<br/> U.S. federal agents made the discovery after stopping a cargo truck seen leaving a warehouse.<br/> They found three tons of marijuana in the vehicle, and another 6.5 tons in the warehouse.<br/> Mexican authorities found another eight tons on the south side of the tunnel, much of it branded with Captain America labels.<br/> A Mexican general said the tunnel was operated by the powerful Sinaloa cartel.<br/> Tijuana is the principal gateway for drugs entering California from Mexico.<br/> Drug cartels have dug scores of tunnels under the U.S.-Mexico border in recent years.<br/> Nick Rowlands, Reuters.
