US Border Patrol agents recently discovered and disabled a nearly 3,000-foot-long narcotics smuggling tunnel sitting beneath the US-Mexico border.

Agents found the tunnel — which linked Tijuana and San Diego — in early April while it was actively under construction. 

The tunnel stretched beneath a section of the Otay Mesa Port of Entry, with plans for it to surface near or within a commercial warehouse in San Diego, as stated by US Customs and Border Protection.

Upon entry, officials encountered “highly sophisticated” features, including barricades likely intended to obscure the entrance from law enforcement, the announcement mentioned.

The tunnel — which reached depths of around 50 feet underground at its deepest point — measured 2,918 feet long, 42 inches tall and 28 inches wide

It was equipped with lighting, electrical wiring, ventilation systems and a track system for transporting large amounts of contraband.

In collaboration with Homeland Security Investigations and Mexican authorities, Border Patrol agents discovered the tunnel’s opening on Monday inside a residence located in the Nueva Tijuana area of Tijuana.

The entrance had recently been covered up with freshly laid tile, according to the announcement.

Thousands of gallons of concrete will soon be poured into the tunnel to prevent it from being used by Foreign Terrorist Organizations, US Customs and Border Protection noted.

“As we continue to strengthen the nation’s air and maritime border security, it’s not surprising that foreign terrorist organizations would resort to underground routes,” Jeffrey D. Stalnaker, acting chief patrol agent of the San Diego Sector, said in a statement. “Disruption of narcotics smuggling tunnels is critical to protecting American lives.”

More than 95 tunnels have been decommissioned in the San Diego area since 1993. 

US Customs and Border Protection did not immediately respond to Fox News Digital’s request for comment.