The Edinburg Police Department confirmed that 17 immigrants were in the back of the trailer, KRPC reported.
There were no ambulances saw on the scene, and Edinburg police did not report any wounds or setbacks.
Officials said the trailer was parked at a parking lot when the people were found. Officials said they knocked on the trailer and heard knocking from the other side, according to an NBC affiliate. In the wake of accepting a call from a relative of a person inside the trailer, Edinburg police said they landed on the scene and started thumping on tractor-trailers.
Edinburg police tell KRGV that Border Patrol will be taking over the investigation.
Before being taken into custody, The Monitor observed a group of more than 10 individuals sitting in a shaded area underneath a tree. The gathering of people were in the end looked before being escorted into a Border Patrol van.
This is a developing story.