(WASHINGTON, D.C.) — As an increased number of unaccompanied minors show up at the southern border, U.S. advocates expressed concern over the overcrowding of detention centers.  With the U.S. immigration system starting to become overwhelmed, detention centers are running out of space to hold the minors for processing.

Lawyers also expressed concern over the condition of the holding centers, citing cases of frightened children unable to contact family members or access the outdoors for fresh air.

Leecia Welch, Senior Director of Child Welfare at the National Center for Youth Law, said, “What we saw this time was a lot of very young, very scared children.”

Children who are as young as one, but the majority in their mid teens, are held in tents — with some being held longer than a week — sparking concerns about COVID-19 transmission.

“It just makes it all the more scary for them, because … these are places that no child should have to be in on their own,” adds Welch.

Border Control, when apprehending unaccompanied minors at the border, are placed under Customs and Border Protection custody temporarily as they await being transferred to a resettlement office.

Two U.S. Customs Border Protection officials told ABC News on condition of anonymity said there are currently some 8,800 minors in HHS care.

The Biden administration blames the prior administration for dismantling the U.S. immigration system.

Meanwhile, House Minority Leader Kevin McCarthy on Monday led a delegation to the border at El Paso, Texas, where he called the influx of unaccompanied young people “the Biden crisis” and refuted claims that the issue is a result of the Trump administration.