ANNEX TO THE CONVENTION : Regulations respecting the laws and customs of war on land #Section IV : On the internment of belligerents and the care of the wounded in neutral countries - Art. 57.
Art. 57. A neutral State which receives in its territory troops belonging to the belligerent armies shall intern them, as far as possible, at a distance from the theatre of war.
It can keep them in camps, and even confine them in fortresses or locations assigned for this purpose.
It shall decide whether officers may be left at liberty on giving their parole that they will not leave the neutral territory without authorization.