** ADVANCE FOR SUNDAY, DEC. 31 **A National Guard soldier peers over the vast Otay Mountain Valley as he assists the Border Patrol infrared scope unit as agents search the area for smugglers in San Diego Wednesday, Dec. 20, 2006. The unit directs other agents in the area when they sight smugglers bringing illegal immigrants into the country. (AP Photo/Lenny Ignelzi)
Border Patrol agents found 48 suspected illegal immigrants in the back of a closed truck trailer at a checkpoint in Laredo.
The Laredo Morning Times reported Wednesday that a federal complaint said the driver is facing federal charges.
The complaint said a secondary inspection Friday night, at the Interstate 35 checkpoint, led to the trailer's rear doors being opened and 48 people hiding inside. Their status was not immediately available Wednesday.
The Border Patrol did not immediately return a message Wednesday from The Associated Press.
The National Weather Service said nighttime temperatures in Laredo this week reached the upper 90s.