LAREDO, Texas (AP) — A truck driver has been arrested and Homeland Security authorities are investigating after 14 people in the country without legal permission were found hiding in a box truck at a South Texas Border Patrol checkpoint.

Officials say the 13 males and one female were inside moving boxes marked "fragile." They all were reported in good health.

An initial X-ray of the truck at an inspection checkpoint on Interstate 35 at Laredo detected irregularities that led to a closer examination of the cargo Friday. A dog accompanying agents also alerted officials.

Authorities say all 14 people being smuggled into the U.S. were from Mexico.