Mexican patrols have discovered a suspected drug tunnel under construction between Tijuana and the US city of San Diego.
Mexico's military uncovered the third such tunnel found this year inside a company warehouse near a busy customs area between both nations.
The sophisticated 125-metre tunnel did not yet have an outlet on the US side but included lighting, ventilation and metal runners.
Two other such tunnels were discovered in Mexico in April, one found in Mexicali used a US home's garage as an entrance.
Last month Joaquin "El Chapo" Guzman, the head of the Sinaloa drug cartel, escaped from a maximum security jail through a 1.5km-long tunnel.