Drug smuggling tunnel with rail system uncovered on US-Mexico border

The ventilated underground passage runs the length of a football field and also contains reinforced walls and electricity supply

US authorities have discovered an underground smuggling tunnel on the California-Mexico border that runs the length of a football field and contains reinforced walls, electricity, ventilation and a rail system.

Investigators discovered the tunnel, which led to a warehouse in an industrial area on US soil, last week. The tunnel is located about half a mile (0.8km) from the Otay Mesa border crossing between Tijuana and San Diego, in an area where more than a dozen others have been discovered in the past two decades.