Federal officers in Arizona and Mexico discovered a cross-border tunnel in Nogales on Wednesday, officials said.
The smuggling tunnel had not been completed.
Border Patrol agents found the tunnel west of the DeConcini Port of Entry.
After seeing freshly disturbed dirt within the channel floor of a drainage system, authorities discovered a tunnel originating in Mexico and extending 133 feet into the United States.
The tunnel, measuring about 3 feet high, did not open up on the Arizona side.