TUCSON, Ariz. — Border Patrol agents say they have arrested a southern Arizona man and three other people found hidden in his car trunk who they suspect of being in the U.S. illegally.

Authorities did not name the 31-year-old man from Rio Rico, who initially appeared to be alone in the Dodge Intrepid he was driving when he was stopped Tuesday afternoon at an immigration checkpoint near Amado, Arizona.

Agents found three people, ages 19, 22 and 31 hidden in the trunk. Two are from Guatemala and the third is from Mexico.

The driver, a U.S. citizen, faces smuggling charges while the other three people are being processed for immigration violations.