Related Rule
New Zealand
Practice Relating to Rule 36. Demilitarized Zones
New Zealand’s Military Manual (1992) provides: “The parties to a conflict may agree that a particular area shall constitute a demilitarized zone, in which case military operations may only be carried on in that area to the extent permitted by the agreement.” With respect to the rules and the procedure to be adopted in relation to the establishment of demilitarized zones, the manual refers to Article 60 of the 1977 Additional Protocol I. It also notes that agreements establishing the zones may be oral or in writing, may be arranged either directly or through the medium of a protecting power or any impartial humanitarian organization, or may also arise by way of reciprocal and concordant declarations. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 412(4).
New Zealand’s Military Manual (1992) states:
Any material breach of [the conditions for a zone to be established as a demilitarized zone] releases the other Party from its obligations under the agreement and the zone loses its special status. It shall, however, continue to enjoy the normal protection provided by the customary and treaty law of armed conflict. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 412(5).
The manual further states that “making … demilitarized zones the object of attack” constitutes a grave breach of the 1977 Additional Protocol I. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 1703(3)(d).
New Zealand’s Geneva Conventions Act (1958), as amended in 1987, provides:
Any person who in New Zealand or elsewhere commits, or aids or abets or procures the commission by another person of, a grave breach … of [the 1977 Additional Protocol I] is guilty of an indictable offence. 
New Zealand, Geneva Conventions Act, 1958, as amended in 1987, Section 3(1).