An audio recording was published Monday that appears to capture the voices of young children crying out for their parents at a U.S. immigration detention center. The audio file was first published by the nonprofit news group ProPublica. The recording added to the growing disapproval of the Trump administration’s policy of separating immigration children from their parents at the U.S.-Mexico border. One child, in Spanish, can be heard shouting, “Papa! Papa!” Some are crying too hard to speak. One young Salvadoran girl is heard asking several times if she can call her aunt to ask her to come get her. Human rights lawyer Jennifer Harbury said she received the tape from a whistleblower.