U.S. border agents find smuggling tunnel in San Diego

Border Patrol agents discovered a tunnel running under the U.S.-Mexico border Saturday in San Diego, California apparently used for illegal immigration, authorities said.

Border Patrol Agent Eduardo Olmos said Saturday that agents detained about 30 people including Mexican and Chinese nationals. No drugs were found, he said.

When agents approached a group of people at the site early Saturday morning, some started running and others went back into the tunnel, leading to its discovery, Olmos said.

The tunnel began in a building in Tijuana, more than 300 feet (90 meters) south of the U.S.- Mexico border and ran past a fence at the Otay Mesa Port of Entry, KNSD-TV reported. Olmos could not confirm where the tunnel started or its length.

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Trucks wait to carry shipments of vegetables from Mexico to the rest of the U.S. at SunFed produce packing and shipping warehouse in Nogales, Arizona, U.S., January 30, 2017. Picture taken January 30, 2017. REUTERS/Lucy Nicholson
Quality Control Inspector Gilberto Nunez, 50, checks vegetables at SunFed produce packing and shipping warehouse in Nogales, Arizona, U.S., January 30, 2017. Picture taken January 30, 2017. REUTERS/Lucy Nicholson
Matt Mandel, VP Operations for SunFed, (R) watches Quality Control Inspector Gilberto Nunez, 50, pack vegetables at SunFed produce packing and shipping warehouse in Nogales, Arizona, U.S., January 30, 2017. Picture taken January 30, 2017. REUTERS/Lucy Nicholson
Workers unload shipments of vegetables from Mexico at SunFed produce packing and shipping warehouse in Nogales, Arizona, U.S., January 30, 2017. Picture taken January 30, 2017. REUTERS/Lucy Nicholson
Nogales, Arizona, U.S. is seen from the abutting town of Nogales, Sonora, Mexico, February 1, 2017. REUTERS/Lucy Nicholson
The international border port crossing to Mexico is seen in Nogales, Arizona, U.S., January 30, 2017. Picture taken January 30, 2017. REUTERS/Lucy Nicholson
Truck driver Howard Casale, 64, prepares to carry shipments of vegetables from Mexico to Boston at SunFed produce packing and shipping warehouse in Nogales, Arizona, U.S., January 30, 2017. Picture taken January 30, 2017. REUTERS/Lucy Nicholson
Mauricio Felix, 38, (R) washes dishes with Alejandro Galindo, 42, in his family's restaurant, Rancho Grande, in Nogales, Arizona, U.S., January 31, 2017. Picture taken January 31, 2017. REUTERS/Lucy Nicholson
Trucks and cars cross the border from Mexico into the U.S. in Nogales, Arizona, U.S., January 30, 2017. Picture taken January 30, 2017. REUTERS/Lucy Nicholson
Matt Mandel, VP Operations, views tomatoes at SunFed produce packing and shipping warehouse in Nogales, Arizona, U.S., January 30, 2017. Picture taken January 30, 2017. REUTERS/Lucy Nicholson
Quality Control Inspector Gilberto Nunez, 50, checks vegetables at SunFed produce packing and shipping warehouse in Nogales, Arizona, U.S., January 30, 2017. Picture taken January 30, 2017. REUTERS/Lucy Nicholson
The U.S. border with Mexico is seen in Nogales, Arizona, U.S., January 31, 2017. Picture taken January 31, 2017. REUTERS/Lucy Nicholson
People in Nogales, Sonora, Mexico are seen through the U.S. border fence as they queue to cross into Nogales, Arizona, U.S., January 31, 2017. Picture taken January 31, 2017. REUTERS/Lucy Nicholson
A woman walks toward the U.S. border port with Mexico in Nogales, Arizona, U.S., January 31, 2017. Picture taken January 31, 2017. REUTERS/Lucy Nicholson
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U.S. Border Patrol Agent David Ruiz patrols the U.S. border with Mexico in Nogales, Arizona, U.S., January 31, 2017. Picture taken January 31, 2017. REUTERS/Lucy Nicholson
The U.S. border with Mexico is seen in Nogales, Arizona, U.S., January 31, 2017. Picture taken January 31, 2017. REUTERS/Lucy Nicholson
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Subterranean tunnels found in the area are most commonly used for drug smuggling, according to the Customs and Border Patrol.

In 2016, federal agents said they seized a ton of cocaine and seven tons of marijuana smuggled through a tunnel in the same area that stretched a half mile beneath the border, which then was the longest one yet unearthed in California, Reuters previously reported.

Authorities said at the time that was the 13th underground passageway discovered along California's border with Mexico since 2006.

Tunnels designed for drug smuggling are often more sophisticated and can include lighting, ventilation or rails that run as deep as 90 feet below the earth's surface, Olmos said. Human smugglers tend to use more rudimentary tunnels, he said.

"This seems to be somewhere in between," he said.

The latest tunnel find is under investigation by the San Diego Tunnel Task Force, led by U.S. Immigration and Customs Enforcement.

(Reporting by Chris Kenning in Chicago; Editing by Lisa Shumaker)

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