At least 200 undocumented migrants including several children were found hidden in a lorry without food or water in north-eastern Mexico.
The migrants were likely the citizens of Guatemala, Honduras and El Salvador which are the major source of illegal migrants being trafficked into the US.
Mexican police said the lorry was stopped at a checkpoint in Tamaulipas state just south of the Texas border. Scanners detected the people hidden inside. They had no food, water or proper ventilation. Twenty-four of the migrants were unaccompanied children, officials added.
Three people have been arrested on suspicion of human trafficking.