ANNEX TO THE CONVENTION : Regulations respecting the laws and customs of war on land #Section III : On military authority over hostile territory - Art. 43.
Art. 43. The authority of the legitimate power having actually passed into the hands of the occupant, the latter shall take all steps in his power to re-establish and insure, as far as possible, public order and safety, while respecting, unless absolutely prevented, the laws in force in the country.