In shelters from Kansas to New York, hundreds of migrant children have been roused in the middle of the night in recent weeks and loaded onto buses with backpacks and snacks for a cross-country journey to their new home: a barren tent city on a sprawling patch of desert in West Texas.
Until now, most undocumented children being held by federal immigration authorities had been housed in private foster homes or shelters, sleeping two or three to a room. They received formal schooling and regular visits with legal representatives assigned to their immigration cases.
But in the rows of sand-colored tents in Tornillo, Tex., children in groups of 20, separated by gender, sleep lined up in bunks. There is no school: The children are given workbooks that they have no obligation to complete. Access to legal services is limited.
These midnight voyages are playing out across the country, as the federal government struggles to find room for more than 13,000 detained migrant children — the largest population ever — whose numbers have increased more than fivefold since last year.
tried to flee.
The children wore belts etched in pen with phone numbers for their emergency contacts. One young boy asked the shelter worker if he would be taken care of in Texas. The shelter worker replied that he would, and told him that by moving, he was making space for other children like him who were stuck at the border and needed a place to live.
testified before Congress that the agency had arrested dozens of people who applied to sponsor unaccompanied minors. The agency later confirmed that 70 percent of those arrested did not have prior criminal records.
“Close to 80 percent of the individuals that are either sponsors or household members of sponsors are here in the country illegally, and a large chunk of those are criminal aliens. So we are continuing to pursue those individuals,” Mr. Albence said.
Seeking to process the children more quickly, officials introduced new rules that will require some of them to appear in court within a month of being detained, rather than after 60 days, which was the previous standard, according to shelter workers. Many will appear via video conference call, rather than in person, to plead their case for legal status to an immigration judge. Those who are deemed ineligible for relief will be swiftly deported.
The longer that children remain in custody, the more likely they are to become anxious or depressed, which can lead to violent outbursts or escape attempts, according to shelter workers and reports that have emerged from the system in recent months.
Advocates said those concerns are heightened at a larger facility like Tornillo, where signs that a child is struggling are more likely to be overlooked, because of its size. They added that moving children to the tent city without providing enough time to prepare them emotionally or to say goodbye to friends could compound trauma that many are already struggling with.
A version of this article appears in print on , on Page A14 of the New York edition with the headline: Migrant Children Are Moved in Darkness to Tent City in Texas