More than 100 unaccompanied minors have been found in eastern Mexico among 343 migrants crammed into a truck trailer, the Mexican government said on Monday, according to AFP.

The migrants from Guatemala, Honduras, El Salvador and Ecuador included several families, as well as “103 unaccompanied minors, most of them from Guatemala,” the National Institute of Migration (INM) said in a statement.

Migrants were discovered on Sunday evening on a road in the state of Veracruz. The driver was absent.

They “were wearing colored bracelets as a means of identification,” the INM said in a statement. These bracelets are commonly distributed by smugglers who transport migrants to the United States border.

The trailer had a double floor. Fans have been installed and ventilation holes have been made in the roof, INM reports.

The minors and families were taken into the care of the social assistance structures of the state of Veracruz, while the adults will have to determine their migrant status with the authorities.

Last Thursday, the INM announced the discovery in the state of Puebla, in the center of the country, of 136 migrants of various nationalities traveling in an unventilated truck. Among them, ten minors were traveling alone.

Thousands of migrants fleeing poverty cross Mexico from Central and South America each year in hopes of reaching the United States.