HARROWING audio recordings that appear to capture the voices of children crying for their parents have provoked outrage over US President Donald Trump’s “zero tolerance” immigration policy.

One child is heard crying “Papa, papa” in the sound file which is claimed to have been recorded at a US immigration detention centre on the Mexican border.

Pressure is mounting on Mr Trump over his policy that sees migrant children held in detention centres apart from their parents after human rights lawyer Jennifer Harbury said she was leaked the recording from a whistleblower last week.