http://en.wikipedia.org/wiki/Illegal_combatant

Article 5 of the GCIII states that their status may be determined by a "competent tribunal" and until such time they are to be treated as prisoners of war.[2] After such "competent tribunals" have determined their status, the "Detaining Power" may choose to accord detained unlawful combatants the rights of prisoners of war as described in the Third Geneva Convention, but is not required to do so.