While the wave of child and teen migrants has dropped off at the U.S. border, detentions of Central American minors are up sharply in Mexico this year.

Mexico's National Immigration Institute says detentions of Central American minors have risen 49 percent compared to the similar period last year. It says about half of the 11,893 underage migrants detained between January and May were travelling alone or with a smuggler.

Two-thirds were between 12 and 17. One third were 11 or younger.

The institute said Monday it was caring for the increased number of children through the country's child welfare agencies before they are deported.

But as in the 2014 U.S. "immigration overload" crisis, there are accusations of inadequate facilities to handle all the minors detained.