A newly discovered tunnel along the U.S.-Mexico border has once again drawn attention to organized crime operations in the San Diego-Tijuana region.

Mexican federal authorities announced the discovery of an underground tunnel in the city of Tijuana that, according to preliminary investigations, may extend into U.S. territory and connect to an area near Otay Mesa in San Diego.

The structure was found during a law enforcement operation at a residence in the Nueva Tijuana neighborhood. Authorities said the tunnel shows signs of sophisticated planning and construction. The passageway is approximately 21 feet deep and nearly 869 feet long, and it is equipped with lighting and ventilation systems that allowed it to operate efficiently.

The property where the tunnel was discovered was under investigation for alleged violations involving firearms, explosives, and drug-related offenses. During the operation, agents seized ammunition, substances believed to be methamphetamine and marijuana, as well as cell phones and various documents that are now part of the ongoing investigation.

The discovery has also attracted the attention of U.S. authorities. Officials with Homeland Security Investigations (HSI) in San Diego confirmed they are participating in a joint operation involving a cross-border tunnel in the Otay Mesa area. However, they said they could not provide additional details while the investigation remains active.

All seized evidence has been placed under the custody of Mexican authorities, while forensic experts and investigators continue gathering information to determine the scope of the activities linked to the underground structure.

The discovery once again highlights the security challenges facing one of the busiest border regions in the world. Authorities on both sides of the border are working to determine the tunnel’s origin, purpose, and potential criminal connections as the investigation continues.