"The United States is running concentration camps on our southern border and that is exactly what they are," Rep. Alexandria Ocasio-Cortez said Monday night in an emotional Instagram live video. "They are concentration camps," she reiterated to her viewers, who flooded the feed with comments.

Sitting in what appeared to be her apartment, the freshman congresswoman criticized the border facilities that currently house undocumented migrants who have crossed into the U.S. and are waiting to be processed. Images from the centers show some migrant children sleeping under foil blankets. Many are kept in small fenced-in areas; some are outdoors.

"I want to talk to the people that are concerned enough with humanity to say that 'never again' means something," Ocasio-Cortez continued in her live video. "The fact that concentration camps are now an institutionalized practice in the 'Home of the Free' is extraordinarily disturbing and we need to do something about it."

The live video, which ended and disappeared from her Instagram, was captured by several people and shared online. Alexandria Ocasio-Cortez/Instagram

The representative from New York said this week, immigrant children were taken to the same concentration camps where people of Japanese ancestry were held in during WWII. Camps were built in states with large Japanese-American populations, including California, Washington and Oregon.

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The Fort Sill Army installation in Oklahoma was also used as an internment camp during this time. Last week, the federal government announced a plan to place as many as 1,400 unaccompanied migrant children in makeshift housing at the base.

This is not the first time since WWII that Fort Sill has been used to hold migrants. In 2014, the installation served as a temporary emergency influx shelter for unaccompanied migrant children, the Office of Refugee Resettlement said, as a result of a migration surge at that time.

The federal government plans to place as many as 1,400 unaccompanied migrant children in makeshift housing on the Fort Sill Army installation in Oklahoma, officials announced Tuesday. Commanche County, Oklahoma

In addition to Fort Sill, the agency said in its statement that it is also considering placing another large-scale facility for unaccompanied migrant children at the Santa Teresa Land Port of Entry in New Mexico.

The Department of Health and Human Services confirmed to CBS News last week that it is not offering the majority of education, legal services and recreation that it is required to provide children in its custody. Spokesperson Mark Weber said that the agency is also required by law to do so during a budget crisis.

In her live video, Ocasio-Cortez said the issue is not just about immigrants: "This is a crisis for ourselves. This is a crisis if America will remain America in its actual principles and values. Or if we are losing to an authoritarian and fascist presidency," she said.

"I don't use those words lightly. I don't use those words to just throw bombs. I use that word because that is what an administration that creates concentration camps is," she continued. "A presidency that creates concentration camps is fascist, and it's very difficult to say that."

Her video faced pushback from the likes of Republican Senator Lindsey Graham. Graham said on Twitter that Ocasio-Cortez was "not lifting a finger to solve the problem" and doing a disservice to "the men and women serving our country" by comparing them to concentration camp guards.

People like @AOC -- who are not lifting a finger to solve the problem -- comparing the men and women serving our country to concentration camp guards do the Congress and country a great disservice. — Lindsey Graham (@LindseyGrahamSC) June 18, 2019

There are more than 160 shelters nationwide. Fort Sill is the second location to be located on federal land. As a result, it will not be subject to state child welfare inspections. The other site not being overseen by state authorities is in Homestead, Florida and is also the nation's largest.

Officials say the Office of Refugee Resettlement's shelters could be insufficient to house what it's calling an "influx" of children. According to agency statistics, ORR took in 40,900 children during the first seven months of the current fiscal year — an increase of 57% from last year.