The desperation and suffering of young migrant children separated from their parents at the US border appear to have been captured in an audio recording.
"I don't want them to stop my father. I don't want them to deport him," one child can be heard saying at the start of the clip, released by investigative nonprofit organisation ProPublica.
Shouts of "Papa!… Mami!" can also be heard, while one child repeatedly pleads for someone to call her aunt, whose telephone number she has memorised and recites to officials.
"I want my aunt to come so she can take me to her house," she sobs. "My mummy says that I'll go with my aunt… and that she'll come to pick me up there as quickly as possible."
The recording gives an apparent insight into the conditions on the southern US border, where migrant families are split up and young children are being kept in cages in camps as part of a controversial clampdown on immigration introduced by Donald Trump's administration.
Human rights attorney Jennifer Harbury said she received the tape from a whistleblower and told ProPublica it was recorded last week, but did not say at which camp.
Agents running the facilities have said everyone detained is given adequate food, access to showers and laundered clothes, as well as medical care.
The UN children's agency joined a growing chorus of condemnation of the policy on Tuesday.
Henrietta Fore, an American who has headed UNICEF since earlier this year, said separating migrant children from their families is "not right", citing "heartbreaking" cases of babies being taken from their parents.
"Detention and family separation are traumatic experiences that can leave children more vulnerable to exploitation… and can impact children's long term development," she said.
"Such practices are in no one's best interests, least of all the children who most suffer their effects. The welfare of children is the most important consideration."
Politicians and religious groups are also among those to have criticised the Trump administration's "inhumane" policy.
Democrat congressman Peter Welch described a camp he visited as "nothing short of a prison", while former first lady Laura Bush said the images are "eerily reminiscent of the Japanese American internment camps of World War II".
Former director of the CIA, Michael Hayden, tweeted a black and white photo of Birkenau, the Nazi concentration and death camp in Poland, and wrote underneath: "Other governments have separated mothers and children."
Celebrities including singer John Legend and actor John Cusack are among those who have condemned the action.
Nearly 2,000 children have been taken from their parents since the attorney general, Jeff Sessions, announced the policy directing Homeland Security officials to refer all cases of illegal entry into the US for prosecution.
This means parents are sent for federal court proceedings and separated from their children, who cannot be jailed under US law.
Around 80 people pleaded guilty to immigration charges on Monday, including some who asked the court what was going to happen to their sons and daughters – to which the judge replied that he did not know.
Republican senator Ted Cruz, of Texas, has said he plans to table emergency legislation intended to keep immigrant families together.
"All Americans are rightly horrified by the images we are seeing on the news, children in tears pulled away from their mothers and fathers," he said. "This must stop."
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Mr Trump has emphatically defended the policy, and blamed the Democrats for blocking his reforms to immigration legislation.
"The United States will not be a migrant camp and it will not be a refugee holding facility," he said. "Not on my watch."