Distraught children separated from their parents in US detention centres can be heard crying in an audio clip released by ProPublica on Monday.
The eight-minute sound clip was recorded last week inside a US Customs and Border Protection Detention Centre and is one of a number of documents released in recent days showing the toll the detention centres is taking on children.
Government officials have banned journalists from using cameras or conducting interviews with the children who are kept inside locked 'cages'.