US officials say they have uncovered a major drug-smuggling¹ tunnel under the border with Mexico and seized an estimated 14 tons of marijuana.

美国官员称，他们在与墨西哥交界处发现一处大的毒品走私隧道，并缴获了大约14吨大麻。

US police said the tunnel was 400 yards long
Customs officials said the tunnel linked warehouses² in Tijuana, Mexico, and Otay Mesa, in California.

Pictures of the tunnel showed wooden supports and electric cables indicative（象征的） of lighting³ and ventilation systems（通风系统） .

Dozens of such tunnels have been found in recent years as US police have cracked down on overland（陆上的） smuggling.

More than 30 have been discovered this year, Mexican authorities said, according to AFP news agency.

The tunnels are also used to smuggle⁴ illegal migrants into the US.

Nine or 10 tons of marijuana was found on the US side of the tunnel while Mexican police seized five tons on their end, said Derek Benner, a special agent with the US Immigration and Customs Enforcement agency.

The tunnel was estimated at 400 yards (365m) in length but it was not clear how deep or wide it was.

Other tunnels found by US police have included tracks, lights and ventilation systems.