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 Trump administration has pushed third-party countries to accept deportees whose home countries will not accept them.

The United States sent five immigrants it says were convicted of serious crimes to the African nation of Eswatini, the U.S. Department of Homeland Security said -- an expansion of the Trump administration's largely secretive third-country deportation program.