But as Iraq prepares to repatriate citizens now held in ­Syria, humanitarian groups have been resisting efforts to move them to a single detention facility, fearing this could create prison camp conditions that would prevent them from reintegrating into society and, in some cases, further radicalize them.

Objections from humanitarian groups have already scuttled a proposal to set up a new camp near Tal Afar in the northern province of Nineveh. Senior Iraqi officials, however, remain opposed to the idea of scattering the Islamic State returnees, mostly women and children, among existing displacement camps around the area, according to high-ranking figures in the Displacement Ministry and parliament.

“The goal is to select a special place to contain those people,” said one Iraqi official, who spoke on the condition of anonymity because he was not authorized to discuss the issue. “It’s for security reasons, but also to keep them alive. If they return to their areas, they’ll be singled out for revenge attacks by people who lost relatives to the Islamic State.”