The Sudanese government has summoned both the United States and South Sudan ambassadors following the re-arrest of Christian convert Miriam Ibrahim over "forged" travel documents.
Sudan's National Intelligence and Security Services agency said that Ibrahim had attempted to travel to the US using an American visa and documents issued by South Sudan.
A post on Facebook, in which the agency referred to her using her Muslim name, read: "The airport passport police arrested Abrar after she presented emergency travel documents issued by the South Sudanese embassy and carrying an American visa."
"The Sudanese authorities considered (the action) a criminal violation, and the Foreign Ministry summoned the American and South Sudanese ambassadors," it added.
More top news
Wintry weather into the weekend
Jeremy Hunt could impose controversial new contracts for junior doctors by Monday, ITV News Political Editor Robert Peston has learned.
A new video has emerged online purporting to show a four-year-old British boy blowing up a car and killing three prisoners on behalf of IS.