“Mami!” the children’s voices cry out, between sobs. “Papá!”

A recording of immigrant children calling out desperately for their parents after being separated from them by United States immigration authorities was released on Monday by the investigative news site ProPublica.

The recording, nearly eight minutes in length, added disturbing and intimate notes to the debate over the Trump administration’s practice of separating children from their parents when families are detained at the border.

ProPublica said in an article accompanying the audio clip that it was recorded last week inside a U.S. Customs and Border Protection detention center. Ten Central American children who were separated from their parents by immigration authorities are heard in the clip, along with some adults.

The recording is one of a number of documents and accounts that have emerged in recent days showing the toll the practice is taking on children, even though government officials have forbidden journalists who tour the detention centers for migrant children from using cameras or conducting interviews with the children.