The Office of Refugee Resettlement is reportedly holding several unaccompanied minors in off-the-book shelters throughout the United States, an investigation by Reveal found.

The total number of sites is unknown, but Reveal reports that there are at least five such shelters in Arkansas, Oklahoma, Pennsylvania, and Virginia. They are holding at least 16 boys and girls after they were transferred from known refugee shelters. The shelters reportedly specialize in caring for children with mental health and behavior challenges.

The federal government has not made the existence of the shelters public "or even disclosed them to the minors' own attorneys in a landmark class action case," writes Reveal.

Holly Cooper, an attorney who represents the class of unaccompanied minors in the agency's care, said the government did not report every minor's location and believes the ORR continues to withhold information about other locations.

The ORR's standards do allow for out-of-network transfers if the federal facilities cannot provide specialized services. But failing to provide both attorneys for the detained children and a detailed census of the minors in custody appears to violate "longstanding rules for the care of immigrant children," such as the Flores Agreement. Former ORR Director Robert Carey said there was no such arrangement for migrant children in 2015 and 2016, as far as he knew.

The ORR has not yet commented on Reveal's report, though the office did acknowledge the request. Read the full report at Reveal. Tim O'Donnell