Border Patrol agents arrested 30 immigrants suspected of crossing a Southern California border Saturday through an underground tunnel, federal authorities said.
Officers found a crude opening and a ladder inside the tunnel north from the Otay Mesa border entrance shortly after 1 a.m., U.S. Customs and Border Patrol said in a statement.
Authorities took 23 Chinese citizens and seven Mexicans into custody for questioning.
Some of the immigrants tried getting back into the tunnel, but it’s unknown if anyone made it back to Mexico, a CBP spokesman told The San Diego Union-Tribune.
The San Diego Tunnel Task Force and Homeland Security officials are on the scene and coordinating with Mexican law enforcement officials in the investigation.
Authorities believe the tunnel is an extension of an incomplete tunnel previously found by Mexican officials.
Underground tunnels are nothing new, border agents said. “While subterranean tunnels are not a new occurrence along the California-Mexico border, they are more commonly utilized by transnational criminal organizations to smuggle narcotics,” CBP said.
“However, as this case demonstrates, law enforcement has also identified instances where such tunnels were used to facilitate human smuggling.”