The government said Tuesday that it plans to triple the amount of space for migrant children traveling without a parent at the Tornillo immigrant detention camp so that up to 3,800 of the children can be held there.

That’s a 20 percent increase in the number of beds for unaccompanied minors, now at 12,800, in the controversial network of more than 100 shelters overseen by the U.S. Department of Health and Human Services.

It comes as the length of stay for unaccompanied minors has lengthened to an average of 59 days — nearly double what it was four years ago.

The expansion of the facility in the desert community of Tornillo southeast of El Paso follows growing outrage over the detention of young migrants who cross the U.S. border, mostly Central Americans, and an increase in the number of reports of sexual and medical abuses of children at the detention centers run by government contractors.

Scrutiny of the detention program has intensified since the Trump administration officially announced in April a "zero-tolerance" policy at the border that led to the separation of more than 2,600 children from their immigrant parents.

Those children were placed in shelters that normally served minors who traveled alone. The policy was rescinded June 20.

TORNILLO, TX - JUNE 24: Filmmaker Rob Reiner (2nd R) his wife Michele Reiner (L) and their daughter Romy Reiner (2nd L) speak with Department of Homeland Security police officers near the tent encampment recently built at the Tornillo-Guadalupe Port of Entry on June 24, 2018 in Tornillo, Texas. The Reiner family joined others to protest the separation of children from their parents after they were caught entering the U.S. under the administration's zero tolerance policy. (Photo by Joe Raedle/Getty Images) (Joe Raedle / Getty Images)

Family separations “are not driving this need,” said Kenneth Wolfe, an HHS spokesman. Wolfe said the Tornillo expansion is based on the number of new arrivals into the shelter program operated by the Office of Refugee Resettlement within HHS.

Wolfe called the Tornillo site, near El Paso, a temporary shelter location and said it will stay open through the end of this year. Tornillo, essentially a tent city camp, was the site of a large Father’s Day protest this year because some separated minors were detained there.

Apprehensions of unaccompanied minors by the Border Patrol have been increasing and already have surpassed totals from fiscal years 2015 and 2017. Through July, about 41,300 unaccompanied minors have been detained, according to U.S. Customs and Border Protection statistics.

Migrant families have been apprehended in much larger numbers. Already, fiscal 2018 is a record year with about 78,000 arrests in the first 10 months.

But overall apprehensions along the border are down significantly from their high of about 1.6 million in fiscal year 2000. Through the first 10 months of this year, there have been about 318,000 border apprehensions.