Human smugglers packed 20 illegal immigrants into the back of a tractor-trailer rig in South Texas.

Laredo Sector Border Patrol agents assigned to the Hebbronville Station observed a tractor-trailer approaching the FM 1017 immigration checkpoint early Tuesday morning. As the driver presented himself for inspection by the agents, a K-9 agent alerted to the presence of drugs or human cargo, according to Laredo Sector officials.

A secondary inspection of the trailer revealed 20 illegal immigrants hiding inside the trailer. The agents checked out the illegal immigrants and determined they were in good health after being locked in the trailer with no air circulation.

“CBP not only strives to protect the American people from all dangers but to prevent deaths and stop unscrupulous smugglers who put immigrants’ lives at risk,” Laredo Sector Acting Chief Patrol Agent Jason D. Owens said in a written statement. “This interdiction is a clear representation of our commitment to safeguard those values.”

Owens has spoken to Breitbart Texas on many occasions about the abuses faced by illegal immigrants at the hands of cartel-connected human smugglers. Those include the beatings and robbery migrants receive at the hands of human smugglers in stash houses all along their journey to the U.S. and across the border. They also include the potentially deadly conditions under which smugglers place their human cargo with little regard for their health or safety.

Agents determined the 20 migrants came to the U.S. from El Salvador, Honduras, and Mexico. The driver, a U.S. citizen, and the 20 illegal immigrants were arrested on human smuggling and immigration violation charges, officials said.

Elsewhere in the Laredo Sector, agents found a group of 96 illegal immigrants, many of whom were lucky to be alive after a pickup truck they were being carried in crashed into a guardrail along Highway 44 near Freer, Texas, Breitbart Texas reported on Tuesday.