A "highly sophisticated" drug tunnel running between Mexico's Tijuana city and the US city of San Diego has been unearthed, CNN reported Thursday.
The tunnel was discovered by the San Diego Tunnel Task Force and it was shut down, US immigration and customs enforcement spokesperson Virginia Kice was quoted as saying.
"We were able to shutter it before it was utilized to bring drugs into the interior," Kice said.
Like a 600-yard tunnel discovered along the border in November 2010, this tunnel had lighting and a rail system.
The earlier tunnel connected a warehouse in Tijuana with one in the Otay Mesa industrial area of San Diego.
Drug cartels on the US-Mexico border have become so powerful and sophisticated in recent years that many areas along the border have become patches of uncontrollable violence, according to experts.