On Tuesday, U.S. and Mexican authorities confiscated 14 tons of marijuana and discovered a 400-yard tunnel that linked Tijuana and San Diego. Agents from Immigration and Customs Enforcement say the tunnel had recently been completed and was outfitted with electricity, ventilation, and structural supports.

Agents discovered the tunnel after staking out a warehouse near the Otay Mesa Port of Entry. Earlier that day, agents pulled over a small cargo truck leaving the facility. Inside they found three tons of marijuana. The bust led to a search of the warehouse, where 6.5 additional tons of pot were found, along with the tunnel.

After receiving word of the bust, authorities in Mexico located the other entry to the tunnel, confiscating an additional 5-6 tons of pot there.

According to the Los Angeles Times, Mexican general Gilberto Landeros Briseno told media outlets in Mexico that many of the packages had pictures of Captain America on them. The image is often used by the Sinaloa Cartel in Tijuana.

"The drug cartels mistakenly believe they can elude detection by taking their contraband underground, but, again and again, we've been able to find these tunnels and shut them down, said Derek Benner, the agent in charge of ICE Homeland Security Investigations in San Diego.

It is the sixth tunnel found in San Diego in four years' time.