The Trump Administration has opted to use an Army base in Oklahoma to hold growing numbers of immigrant children in its custody after running out of room at government shelters.

Fort Sill, an 150-year-old installation once used as an internment camp for Japanese-Americans during World War II, has been selected to detain 1,400 children until they can be given to an adult relative, according to the U.S. Department of Health and Human Services.

The agency said Fort Sill will be used “as a temporary emergency influx shelter” to help ease the burden on the government as it prepares to house a record number of minors even though it already operates about 168 facilities and programs in 23 states.

Health and Human Services said in a statement that it has taken about 40,900 children into custody through April 30. That’s a 57% increase from last year, which is a rate on-pace to surpass the record figures in 2016, when 59,171 minors were taken into custody. The agency had assessed two other military bases before selecting Fort Sill.

The children would be held inside facilities that are separate from the general on-base population. HHS personnel, not American troops, will oversee them.

Using military bases in this way is not new. In 2014, the Obama Administration placed around 7,700 migrant children on bases in Texas, California and Oklahoma, including Fort Sill. The temporary shelters were shuttered after four months. Last year, the government evaluated several military bases to shelter migrants, but ultimately decided not to use the facilities.

However, it appears unavoidable this year. Apprehensions of children at the border are already nearing record numbers. U.S. Customs and Border Protection released data last week that showed the figures had skyrocketed to 56,278 at the end of May, a 74% increase over last year. The influx of migrants, mainly from Central America, is straining an already exhausted system, U.S. officials say. Several children have died while in U.S. custody since last year.

Fort Sill, located southwest of Oklahoma City, was one of several internment camps where Japanese-Americans were held during World War II. Between 1942 and 1946, the U.S. government forcibly removed an estimated 120,000 men, women and children from their homes and incarcerated them across the country. Fort Sill was later used to hold German prisoners of war.

Write to W.J. Hennigan at william.hennigan@time.com.