AbstractDeprivation of liberty for security reasons is an exceptional measure of control that may be taken in armed conflict, whether international or non-international. Administrative detention of persons believed to represent a threat to State security is also being more and more widely practised outside of armed conflict situations. This paper argues that both internment and administrative detention are insufficiently elaborated from the point of the view of the protection of the rights of the persons affected. Drawing on international humanitarian law and on human rights law and standards, the paper proposes a set of procedural principles and safeguards that should — as a matter of law and policy — be applied as a minimum to all cases of deprivation of liberty for security reasons.