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.

Lawyers for the immigrants, who aren’t from South Sudan, contend the deportations violate a court order after a previous attempt to send some people to Libya.