Drug tunnel discovered in Mexico A sophisticated drug-smuggling tunnel has been uncovered along Mexico's border with the US. The passageway, which starts under a sink inside a warehouse in the city of Tijuana, stretches towards San Diego in California. It has not been completed and does not cross the border. Army officials say they made the discovery after a man fled the scene in Mexico. We found all of this rubbish and recyclable material. We started to look at why the individual ran away, and then we found a tunnel," said General Gilberto Landeros Briseno. Earlier this month, a separate, completed passageway was found - running to an unopened business in San Luis in Arizona. It was kitted out with lights and ventilation and carts, used to transport drugs across the border. Under pressure from tightened security on the surface, Mexican cartels have increasingly resorted to going underground to carry out their illegal activities. Dozens of passageways have been uncovered over recent years. More about: Drug trafficking, Mexico, USA