Authorities find longest tunnel under Mexican border

Federal authorities are trying to determine what was smuggled through a sophisticated tunnel into the United States from Mexico that they are calling one of the longest ever found.

"Whether the tunnel was used for smuggling aliens, smuggling narcotics or a worst case scenario, some sort of weapon, we don't know," Michael Unzueta, special agent in charge of Immigration and Customs Enforcement, said. Federal authorities who uncovered the 731m tunnel brought in a forensic team to look for fingerprints and DNA, and to sample the air and wall, to determine how long it has been in use and what it was used for.

The tunnel had cement walls and supporting planks, was no less than 1.2m-tall and wide, and ran as far as 18m underground, Unzueta said. It had lighting and ventilation, and a pumping system to drain groundwater.

"We believe this tunnel is, in fact, the largest tunnel ever found on the Southwest border," he said.

The passageway links a warehouse in Otay Mesa, California, with a warehouse near Tijuana international airport in Mexico. The US Drug Enforcement Administration (DEA) found 90kg of marijuana on the US side, while Mexican authorities said they discovered 2 tonnes of the drug on that side of the border.

- REUTERS