EDINBURG, Texas (ValleyCentral) — On Sept. 9 Rio Grande Valley Sector Border Patrol agents and other law enforcement agencies disrupted five smuggling attempts.

On Friday, Falfurrias Border Patrol Checkpoint agents referred a truck pulling a flatbed trailer carrying a large wooden box to the secondary inspection area.

A search revealed five migrants trapped inside. The box was completely sealed and secured down with cargo straps with no means of escape for the occupants.

Agents determined the migrants were unlawfully in the U.S. while the driver was an American citizen.

The agency’s media release said, in total, 137 arrests were made from the attempted smugglings.