Mexican authorities reported finding more than 600 migrants on Thursday night in trucks near the U.S.-Mexico border, The Associated Press reported.
The migrants were found in six trailers near a military checkpoint on a highway in the state of Tamaulipas, the outlet reported.
The trucks appeared to have left the state of central Puebla and were headed for Monterrey, which is a hub for reaching various points along the border.
A total of 642 migrants from Central America were discovered, of which 564 were from Guatemala. Some migrants were from Honduras, El Salvador, Nicaragua and Belize, AP reported.
More than half of the migrants were children, of which nearly 200 were unaccompanied.
Authorities had to move the trailers to state police facilities to cut them open because they had padlocks. Forty of the migrants were evaluated for malnutrition and dehydration, and nine of the migrants tested positive for COVID-19, according to the outlet.
Tamaulipas is popular for migrant smuggling because it is the border state closest for Central American migrants, the AP noted.
Central American migrants often make the dangerous journey north hoping to enter the U.S. for a better life away from their home countries.
In early September, a caravan with 400 migrants, mainly from Haitians and Central Americans, were reported to have left the Mexican city of Tapachula in route to the U.S.