The Border Patrol has discovered 61 suspected illegal immigrants from Mexico inside a tractor-trailer on Interstate 8 near San Diego.

Border Patrol agents discovered them inside the eastbound truck during a vehicle stop Saturday night, about 45 miles east of San Diego. They were hiding behind bales of cardboard.

The agency said Monday that it arrested the driver, 29-year-old Jose Pina Flores, who will be charged with immigrant smuggling. The Border Patrol says the Mexican man admitted being in the U.S. illegally.

No injuries were reported.