Underage migrants held at the Border Patrol's holding facilities in Yuma have reported poor conditions, as well as allegations of misconduct and even sexual assault at the hands of U.S. border agents.

The accusations are detailed in reports compiled by case managers working for the Department of Health and Human Services, which takes custody of migrant youths after they've been processed at the U.S.-Mexico border, NBC News reported Tuesday.

The Arizona Republic has not reviewed the reports. But these accusations, the first to come out of Arizona, surfaced amid renewed scrutiny on the federal government's treatment of migrants at the border.

The U.S. Department of Homeland Security's watchdog Office of the Inspector General released two reports earlier this month calling on Customs and Border Protection — the agency that oversees Border Patrol — to address serious problems with overcrowding and squalid holding conditions at Border Patrol facilities in El Paso and the Rio Grande Valley.

Examples of sexual assault and misconduct in Arizona include a 15-year-old Honduran girl who reported that a male agent had groped her during a pat down in front of other officers.

A 16-year-old Guatemalan boy alleged that after migrants made complaints about the food and water, the agents took away the mats in their cells, making them sleep on the concrete floor.

In a statement, Customs and Border Protection said they take all allegations seriously and that the agency investigates all formal complaints, noting that the agency provides several ways to report misconduct.

"The allegations do not align with common practice at our facilities and will be fully investigated," the statement read. "It’s important to note that the allegation of sexual assault is already under investigation by the Department of Homeland Security’s Office of Inspector General."

However, President Donald Trump has as recently as Sunday called previous allegations of misconduct and poor conditions at other Border Patrol facilities "phony and exaggerated."

The Yuma Sector, which covers the western third of Arizona's border with Mexico, has seen a dramatic rise in the number of migrant families and minors. It's been the third-busiest crossing area along the entire border, behind El Paso and the Rio Grande Valley.

From January to May, agents apprehended 37,235 migrants traveling as families or unaccompanied minors, according to CBP statistics. A sector-by-sector breakdown for the month of June is not yet available.

In March, Border Patrol officials in Yuma began to release migrant families directly into that border community, stating that they didn't have the capacity to hold them, even for short periods of time.

The sector said it had the capacity to hold 400 migrants at any given time at its three facilities, but were routinely above capacity.

Last month, border officials in Yuma erected tent facilities — similar to the ones in operation in Texas — to house an additional 500 migrants.

Have any news tips or story ideas about the U.S.-Mexico border? Reach the reporter at rafael.carranza@arizonarepublic.com, or follow him on Twitter at @RafaelCarranza.

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