The shelters were intended for children under the age of 12, referred to as “tender age” detainees, who are entering the detention system in ever-larger numbers under the Trump administration’s practice of separating children from parents who enter the country illegally.

Many are toddlers and babies and require special care, and their numbers have been rising since last month, when the government enforced a “zero tolerance” policy on people crossing the border. Estimates suggest that more than 2,400 children under the age of 12 are now in federal custody, including many who have been separated from their parents.

But on Wednesday, faced with the intense criticism over the shelters and the separation of families, President Trump retreated, signing an executive order that would detain parents and children together. For now, it seems the separations will stop, but it remains unclear what will happen going forward. A Health and Human Services official said that children already separated will not be immediately reunited with their parents while the adults remain in custody during their immigration proceedings.

The executive order came just hours after reports that three centers in southern Texas — in Brownsville, Combes and Raymondville — were being outfitted to accommodate younger children.