ICRC Info : [Humanitarian law\Protected persons and property\Civilians in the power of the enemy]
© ICRC/ref: RU-N-00039-29 Civilians are entitled to protection when, as the result of an international armed conflict or of occupation, they find themselves in the hands of a party of which they are not nationals.
See the Fourth Geneva Convention relative to the Protection of Civilian Persons in Time of War of 12 August 1949, in particular Article 4.
See also the following sections:
International humanitarian law: Occupied territory and Conduct of hostilities
ICRC Activities: Protecting civilians in war time