Mexico is studying a change in the way it handles the migrants who have been overwhelming its facilities near the border with Guatemala, and may try to keep more of them in newly constructed voluntary shelters rather than in detention facilities.

The director of the National Immigration Institute tells The Associated Press this week that migrants requesting asylum or certain other visas would be free to come and go from the facilities. Tonatiuh Guillén says the first such shelter would be built in Chiapas near the southern border.

Mexico has been swamped by the flow of U.S.-bound migrants, especially Central American families with children, in recent months, many of whom have travelled in caravans. It has sharply increased the number of migrants it detains and deports.