Five immigrants deported by the United States to the small southern African nation of Eswatini under the Trump administration’s secretive third-country program are in prison, where they will be held in solitary confinement for an undetermined time.

The administration has made the practice of third country deportations central to its sweeping immigration policy.

The Trump administration deported five migrants from Cuba, Jamaica, Laos, Vietnam and Yemen to the tiny African nation of Eswatini on Tuesday, the Department of Homeland Security announced. The big picture: The deportation flights came after the Supreme Court last month allowed the administration to resume deportations of migrants to third countries that were not their place of origin.