The National Institute of Migration (INM) said yesterday the huge number of children, from different nations in Central America, were discovered in just a single one-week period in March.
The figure included some 163 children who were abandoned because they were not traveling with an adult family member or an acquaintance, the INM said in a statement.
In many cases, the children had been left in dangerous or difficult transit points by guides who had been paid between USD 3,000 and USD 5,000, it said.
"The children showed signs of extreme fatigue, foot injuries, dehydration, disorientation and not knowing where they were abandoned," it said.
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Authorities arrested nine suspected traffickers in connection with the case.
INM has said the numbers of immigrant children traveling alone through Mexico "has increased significantly" in recent months.
Some 140,000 undocumented immigrants, the vast majority from Central America, attempt to make the perilous journey through Mexico into the United States every year.
Many travel with children and trust "coyotes" to guide them across the border into the United States.