In the uproar over immigrant children being separated from their parents at the US-Mexico border, one question keeps coming back up: Where are all the girls?

Wednesday night, the Department of Health and Human Services gave a partial answer by releasing a few photos — but members of Congress aren’t satisfied.

LET’S STORM TWITTER Use the hashtag #WHEREARETHEGIRLS? Ready...Set...Go! — Rep Frederica Wilson (@RepWilson) June 21, 2018

Nearly 30 percent of the unaccompanied minors who have entered the US have been girls, according to a figure released by HHS. But girls (and babies and toddlers) haven’t been shown in the photos of shelters where migrant children are being kept. And little has been shared about where girls are sent after they are separated from their parents and put into HHS custody.

For days, HHS officials seemed resistant to disclose this information, even as lawmakers and reporters pressed the agency on the question — prompting growing concern from immigration advocates and a flurry of social media activity asking #WhereAreTheGirls.

Where are the girls? I fear that they could be victims of human trafficking and want to be sure they are free from any pressure, know their rights and know how to report any abridgement of those rights. #KeepFamilesTogether pic.twitter.com/AHiHmmxqM4 — Rep Frederica Wilson (@RepWilson) June 20, 2018

I am increasingly uneasy that there are no photographs released by DHS of any of the facilities for girls who have been separated from their parents. The American public deserves to know and see what’s happening to all of these children. — Brian Schatz (@brianschatz) June 20, 2018

In the letter, we ask @DHSgov and @HHSGov to give specifics as to how many children have been separated, how many facilities are housing them, how their safety and care are being ensured, and what the plans are for family reunification. #WhereAreTheGirls — Rep. Debbie Dingell (@RepDebDingell) June 20, 2018

Immigration advocates have highlighted numerous concerns about threats that girls, especially, could encounter in detention, according to Time’s Abby Vesoulis:

Migrant rights groups say they are concerned about the risks that girls and young women face in detention, noting issues such as pregnancy, sexual assault, menstruation and psychological trauma from assault and rape they faced in their home countries.

A facility in Houston is accused of improperly medicating migrant children, both boys and girls. And at a detention center for boys in Virginia, teenagers who crossed the border alone were allegedly beaten and handcuffed — cases that have raised bigger questions about how shelters treat children and highlighted how much we don’t know about where they’re being held.

On Monday, DHS Secretary Kirstjen Nielsen didn’t do much to ease concerns, deflecting a query on the issue during the White House’s press conference. “I don’t know,” she said simply, and directed reporters to consult HHS.

Rep. Mark Pocan (D-WI), however, provided some insight following his visit to a Brownsville, Texas, shelter, telling the Washington Post, “There are separate facilities for younger children; there are separate facilities for girls.”

A lot of you have asked where the girls and younger children are held. The former Walmart detention facility houses boys 10-17. Girls and younger children are held at separate facilities. Unfortunately, some are as far away as Miami and New York. #wherearethegirls — Rep. Mark Pocan (@repmarkpocan) June 18, 2018

HHS offers some answers

On Wednesday evening, the agency finally released photos and video that offer some more concrete details. (HHS also shared some images on Tuesday, but those were dated to 2016, before the Trump administration took office.)

Unaccompanied girls have been sent to at least two coed shelters located in Homestead, Florida, and Bristow, Virginia. It was not immediately clear what proportion of these girls had been separated from their families versus crossing the border alone. The agency also didn’t say how many other facilities are housing girls, or where they might be located.

The Homestead facility — a former Job Corps site that is currently holding more than 1,100 children — was reopened earlier this year, after it was shut down in 2017 following a steep dip in the number of illegal border crossings, according to the Miami Herald. Sen. Bill Nelson and Florida Rep. Debbie Wasserman Schultz were both barred from entering the Homestead location when they attempted to do so earlier this week.

The company running this facility told us we would be welcomed to tour the facility. HHS then denied us entry and said that they need “two weeks notice” to allow us inside. That’s ridiculous and it’s clear this administration is hiding something. — Senator Bill Nelson (@SenBillNelson) June 19, 2018

The Bristow facility, meanwhile is tied to the nonprofit Youth for Tomorrow, an organization started by Joe Gibbs, the former coach of Washington, DC’s football team, according to CNN.

HHS photos of the facilities show large gymnasium-like rooms packed with bunk beds along with children eating in a cafeteria and sitting in an auditorium. The way the photos are cropped makes it hard to tell how old the children are. Both facilities house teenage children, with the Bristow location also housing “tender age” children, according to HHS.

There’s also some evidence that girls have been sent elsewhere: A report from NY1 found that girls were also being sent to a foster agency as far as New York City. Video captured by the network showed girls headed to a facility late Wednesday night, and Gov. Andrew Cuomo told the network that the girls were among the approximately 2,000 kids recently separated from their parents along the southern border.

There’s a lot we don’t know about how the government is handling separated children

The information HHS released is unlikely to settle the #WhereAreTheGirls question, particularly given the news that the Trump administration has no plan to reunite families separated at the border.

Democratic members of Congress pushed it to the forefront on Twitter again Thursday morning:

3,289 girls are in the unaccompanied alien children program. How many of them were separated from their parents at the border? None of the images of detained migrant children picture girls. Where are the girls? Why doesn't anyone know #WhereAreTheGirls? #FamiliesBelongTogether pic.twitter.com/xkcudDFysT — Rep. Val Demings (@RepValDemings) June 21, 2018

. @SecNielsen, I have a question. Where are the girls? Every American with a conscience wants to know. Young migrant girls came to the U.S. to flee the violence back home. Tearing them away from their families exacerbates their trauma. #WhereAreTheGirls #FamiliesBelongTogether pic.twitter.com/6XARmZFASY — Yvette D. Clarke (@RepYvetteClarke) June 21, 2018

That’s not the only unanswered question. Where are the youngest children being kept? How many babies and young children have been separated from their parents? How can parents and children be reunited?

For now, the Trump administration isn’t saying.