The children are heard calling out for their parents in audio recordings obtained and published by ProPublica.

Handout / Reuters A view inside a US Customs and Border Protection detention facility shows children at Rio Grande Valley Centralized Processing Center in Texas.

A desperate child cries out "Papi, papi," while another girl, in between sobs, asks officials if she can go with her aunt. "I want my aunt to come so I can go to her house," a girl cries to a man identified by ProPublica as a Border Patrol agent. "I have her number!" The news outlet on Monday obtained and published audio recordings of 10 Central American children held in a US Customs and Border Protection detention facility after being separated from their parents. Early in the recording, as children are heard crying and calling out for their parents, a Border Patrol agent can be heard joking, "Well, here we have an orchestra, right?" "What we're missing is the conductor," he adds.

The audio was published as the Trump administration faces backlash for its "zero tolerance" policy prosecuting all people who cross the border illegally. That policy has led to adults being taken into custody after crossing the border, while their children are sent to separate detention centers for minors. The facility was not identified by the publication, and neither was the person who obtained it, who asked they not be named out of fear of retaliation. Instead, ProPublica got the audio from Jennifer Harbury, a civil rights attorney who has lived and worked in the Rio Grande Valley in Texas. ProPublica spoke to the aunt of one of the children heard in the recording, a 6-year-old girl from El Salvador who asks, repeatedly, to be allowed to call her. "Imagine getting a call from your 6-year-old niece," the aunt told ProPublica. "She's crying and begging me to go get her. She says, 'I promise I'll behave, but please get me out of here. I'm all alone.'" The audio circulated rapidly on social media. And as reporters waited for a delayed White House press briefing, several of the recordings could be heard.

Reporters are listening to audio of kids crying in border patrol facility, moments ahead of press briefing @ProPublica https://t.co/h4d8lGVLXj

ProPublica retweeted the video, asking reporters to "Play it" at the briefing. Kirstjen Nielsen, the secretary of the Department of Homeland Security, was asked about the recording during the briefing Monday, but said she had not heard it. "I have been to detention centers," she said when asked about the audio. "I would reference you to the care provided not just by the department of Homeland Security but by the Department of Health and Human Services when they get to HHS."

DHS Sec. Nielsen response to audio of children crying for their parents after being separated from their parents: "I would reference you to our standards" https://t.co/OqZLQCWL1Z