May 21 (UPI) -- The Trump administration violated a previous court order when it deported at least six migrants to South Sudan without providing them an opportunity to challenge their removal to a country where they could be tortured, persecuted or killed, a judge ruled Wednesday.

The migrants were loaded onto a plane on Tuesday and flown to South Sudan less than 24 hours after receiving notice of their removal and without an opportunity to assert claims for protection under the United Nations Convention Against Torture.

The U.S. State Department warns American against traveling to South Sudan due to "crime, kidnapping and armed conflict."

Judge Brian Murphy of the U.S. District of Massachusetts issued his order Wednesday in a case filed in March challenging the Trump administration policy of sending migrants to a country that is not their own without prior notice and a meaningful opportunity to contest their removal on the basis of fear of persecution, torture or death.

Late Tuesday, in response to an emergency order filed by the migrants' attorneys seeking to prevent their clients' rushed removal, Murphy warned the Trump administration against deporting them and ordered it to maintain custody of the migrants if they had already left the United States.