CNN reports that the San Diego Tunnel Task Force, which includes personnel from ICE, US Customs and Border Protection, and the Drug Enforcement Administration, discovered the tunnel, which had not yet become fully operational. "We were able to shutter it before it was utilized to bring drugs into the interior," said ICE spokeswoman Virginia Kice.
The tunnel, which featured lighting and a rail system, was described as "highly sophisticated" by an ICE official.
More than 100 tunnels crossing the US-Mexico border have been discovered since the 1990s. Most of the tunnels have been found in the western border states of California and Arizona, the AP reports. San Diego's clay-like soil is reportedly easy to dig in, leading to popularity as a drug smuggling location. Wednesday's operation uncovered the eighth major tunnel found in San Diego since 2006. The American coastal city borders the Mexican coastal city of Tijuana, both home to more than 1.3 million people.
Major busts in recent years have included a 2011 discovery of a 600-yard tunnel from a warehouse in Tijuana to San Diego which held about 30 tons of marijuana and featured electric rails, lighting, and ventilation.
American authorities have been fighting to keep Mexican cartel activities on the Mexican side of the border.
