Massachusetts federal district judge Brian Murphy ruled May 21 that the flight violated his April order that forbade the government from sending any migrants to third countries without providing them clear information about where they were going and giving them time to raise any concerns about being sent to that country.

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 chartered removal flight with eight men convicted of crimes in the United States, including one from Iowa, took off for South Sudan.

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.

Immigration authorities refused to say what their final destinations would be, but said their home countries had refused to receive the migrants.