Border Patrol on Tuesday returned 100 migrant children to an overcrowded facility in Clint, Texas, which lawyers have recently denounced for its "inhumane" conditions, a Customs and Border Protection (CBP) official told CBS News.

The Border Patrol facility, located in the outskirts of El Paso, has come under scrutiny after independent monitors reported learning of unsanitary, crowded living conditions for as many as 350 detained minors.

According to the attorneys who inspected the facility, older children were taking care of the younger ones. Some young mothers had to wear clothes stained with breast milk. The children also did not have access to soap and toothbrushes, and most had not showered since they crossed the southern border.

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"It is degrading and inhumane and shouldn't be happening in America," Elora Mukherjee, one of the lawyers told CBS News Monday. "The children had not had access to a single shower or bath, they were wearing the same dirty clothing they crossed the border with."

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Border Patrol, which is overseen by CBP, came under widespread pressure to transfer the young detainees into the care of the Office of Refugee Resettlement (ORR), an agency within the Department of Health and Human Services (HHS) responsible for the care of unaccompanied migrant minors in U.S. custody. These children usually remain in HHS custody until a sponsor is found for them.

Border Patrol officers, who are typically the first ones to encounter migrants near the border, are supposed to transfer unaccompanied minors to HHS within three days. Its facilities — like the one in Clint — are not designed to house children.

ORR confirmed to CBS News on Tuesday that 249 of the roughly 350 children held at Clint were moved to its facilities. However, the other children were transferred to other Border Patrol facilities, before ultimately being sent back.

Later on Tuesday, a CBP spokesperson confirmed the agency is the "resuming use" of the Clint station to "streamline" the transfer of migrant children to HHS custody, saying the facility allows officers to separate minors based on age and gender.

"CBP continues to utilize all available resources to prioritize and care for children in our custody and facilitate their expeditious transfer to HHS custody," the spokesperson added.

In recent weeks, HHS has been warning that it is running out of bed space and funds to properly take care of migrant children. The agency is asking for $2.88 billion in emergency funding to increase capacity in children shelters.

An HHS official said the agency is facing a "spike" in referrals of unaccompanied minors, with more than 52,000 children transferred to ORR custody this fiscal year.

Earlier this month, citing a "tremendous strain" on the agency, the department moved to shut down all educational, recreational and legal services offered to migrant children in U.S. custody.

The move is expected to end legal assistance, ESL classes, soccer games and other activities. HHS is also preparing to open a new shelter in south Texas and is inspecting several military bases to potentially house more children.