A federal judge ruled late Tuesday that U.S. officials must retain custody and control of migrants apparently removed to South Sudan in case he orders their removals were unlawful.

A federal judge in Boston has told the Trump administration it must to maintain custody of migrants whom the US government has allegedly flown to South Sudan or other countries in recent days amid heightened concerns over the administration’s aggressive approach to deportations.

Lawyers for the migrants say they were given abrupt notice regarding their clients’ removal to South Sudan, a war-torn nation facing a hunger crisis.

A federal judge has ruled that U.S. officials must retain custody and control of migrants apparently removed to South Sudan in case he orders their removals were unlawful.