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.

The deportees are stuck in Djibouti amid a legal fight over their expulsions. A lawyer for some of the men said she was concerned for their health and welfare.

Eight people from Myanmar, Laos, Vietnam, Cuba, Mexico and South Sudan were on a flight reportedly intended for South Sudan this week.