U.S. border agents over the weekend found 60 illegal immigrants in a refrigerated truck that was hauling broccoli from Mexico to the United States.

U.S. Customs and Border Protection said Monday that agents from the Rio Grande Valley Sector forced the truck to go through a secondary inspection, "after a canine alerted to the discovery of the aliens laying on and within pallets of broccoli lined with a thin sheet of ice."

CBP said the door to the trailer was locked, and the temperature inside was 49 degrees Fahrenheit.

"Medical attention was offered to the rescued aliens but all declined," CBP said. "They were transported to the Falfurrias Border Patrol Station and processed accordingly. The group consisted of 22 Guatemalans, 17 Mexicans, 13 Salvadorans, and eight Hondurans."

CBP said the driver was a Guatemalan national who was arrested and faces federal smuggling charges.

CBP has increasingly faced the dual problem of stopping illegal immigrants but saving them from sometimes dangerous situations due to how they are smuggled across. In recent weeks, CBP has rescued illegal immigrants from extremely hot trailers and has warned repeatedly that migrants are putting themselves in danger.

"RGV Sector Border Patrol urges immigrants against entrusting callous smugglers and we continuously warn against the dangers of people crossing illegally into the United States through dangerous environmental conditions and cases such as this where smugglers jeopardize the lives of aliens by locking them in tractor trailers," CBP said.