Related Rule
New Zealand
Practice Relating to Rule 35. Hospital and Safety Zones and Neutralized Zones
New Zealand’s Military Manual (1992) provides:
A State may declare during peacetime that, in the event of armed conflict, a particular area shall be a safety or hospital zone for the protection of wounded, sick, the aged, expectant mothers and children. On the outbreak of hostilities, the combatants may agree to recognize such areas and zones as being immune from attack and outside the area of hostilities. After the commencement of the conflict, safety and hospital zones may be established in occupied territory as well. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 412(2).
In a section on “General measures for the protection of civilians”, the manual reaffirms the possibility of setting up hospital and safety zones, stating:
In time of peace or after the outbreak of hostilities, belligerents may establish such zones and localities … for the protection from the effects of war of wounded, sick and aged persons, children under fifteen, expectant mothers and mothers of children under seven. Agreements may be concluded between the belligerents concerning mutual recognition of the zones and localities so created. To facilitate the institution and recognition of hospital and safety zones and localities recourse may be had to the good offices of the Protecting Powers and the International Committee of the Red Cross. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 1106.
Concerning the establishment of neutralized zones, the manual states that an agreement is required. It adds:
In the area of operations a neutralised zone may be set up for the protection of wounded and sick or other persons hors de combat as well as non-combatants taking no part in the hostilities or in activities of a military character. The area of the zone and its agreed duration should be detailed in the agreement. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 412(3).