Part II: Rules of Air Warfare#Chapter VI: Duties of belligerents towards neutral States and duties of neutrals towards belligerent States. - Art. 42.
Art. 42. A neutral Government is bound to use the means at its disposal to prevent belligerent military aircraft from entering its jurisdiction and to compel them to land or to alight on water if they have penetrated therein.
A neutral government is bound to employ the means at its disposal to intern every belligerent military aircraft which is found within its jurisdiction after landing or watering for whatever cause, as well as its crew and its passengers, if any.