MEXICO CITY (AP) — Mexican officials said Saturday that in one week they found 370 migrant children who had apparently been abandoned by traffickers paid to take them to the United States.

The children were rescued in 14 Mexican states between March 17 and 24, and the youngest was 9 years old, the National Migration Institute said in a statement, adding that 163 of the children under 18 were found traveling alone.

Most migrants heading through Mexico to the United States come from Central America. They face the threat of accidents, robbery, rape or being forcibly recruited by criminal gangs along the way.  

The institute said the children told officials the human traffickers abandoned them after being paid between $3,000 and $5,000. Sometimes migrants make the journey to the United States, then once established pay traffickers to bring their children north.

It said most of the children showed signs of extreme fatigue, dehydration and foot injuries, along with disorientation at being abandoned at unknown, often dangerous, locations.

Father Heyman Vazquez, director of a refuge for migrants in Huixtla, Chiapas, said he is seeing more and more children making the dangerous trek across Mexico in hopes of reaching the United States.

“Every day more minors make the trip, often entire families with babies, but at other times children as young as 6 accompanied by other children only a bit older than they are,” Vazquez told The Associated Press.