Twenty-three illegal immigrants from China and seven from Mexico used a cartel tunnel to sneak into California. The arrest uncovered an illicit ingress point near a U.S.-Mexico port of entry, revealing the latest structure in a vast network used to smuggle humans and drugs.

The arrest took place in San Diego when U.S. Border patrol agents arrested a group of illegal immigrants who just crossed from Mexico into California, information provided to Breitbart Texas by the U.S. Border Patrol revealed. Some tried to run back to Mexico, triggering a short chase by authorities. While searching the surrounding area near the Otay Mesa international port of entry, agents uncovered a crude opening in the ground with a ladder inside.

In total, authorities arrested 23 Chinese nationals and seven Mexicans. A search of the tunnel did not reveal any narcotics, however as Breitbart Texas has reported, tunnels are a favored method to move illegal immigrants and drugs into the U.S. particularly, on the California and Arizona border areas.

A recently released report by the Government Accountability Office (GAO) found from 2011 through 2016, 67 tunnels were discovered along the U.S.-Mexico Border. Sixty-two out of the 67 were in the Border Patrol’s Tucson, Arizona, and San Diego, California, sectors–which are known strongholds for the Sinaloa Cartel.

Robert Arce is a retired Phoenix Police detective with extensive experience working Mexican organized crime and street gangs. Arce has worked in the Balkans, Iraq, Haiti, and recently completed a three-year assignment in Monterrey, Mexico, working out of the Consulate for the United States Department of State, International Narcotics and Law Enforcement Program, where he was the Regional Program Manager for Northeast Mexico (Coahuila, Tamaulipas, Nuevo Leon, Durango, San Luis Potosi, Zacatecas.)