相关规则
Canada
Practice Relating to Rule 37. Open Towns and Non-Defended Localities
Section C. Attacks on open towns and non-defended localities
Canada’s LOAC Manual (1999) states: “It is prohibited for parties to a conflict to attack, by any means whatsoever, non-defended localities.” 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 4-11, § 109.
Under the manual, a non-defended locality loses its status when it ceases to fulfil the conditions described by the manual (which are the same as those listed in Article 59 of the 1977 Additional Protocol I) or in an agreement between adverse parties to establish that non-defended locality. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 4-11, § 114.
The manual further provides that “making non-defended localities … the object of attack” constitutes a grave breach of the 1977 Additional Protocol I. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 16-3, § 16(d).
Canada’s LOAC Manual (2001) states in its chapter on targeting:
1. It is prohibited for parties to a conflict to attack, by any means whatsoever, non-defended localities.
3. A […] non-defended locality must normally satisfy the following conditions:
a. all combatants, as well as mobile weapons and mobile military equipment, must have been evacuated;
b. no hostile use shall be made of fixed military installations or establishments;
c. no acts of hostility shall be committed by the authorities or by the population; and
d. no activities in support of military operations shall be undertaken.
4. However, the parties to a conflict may agree to the establishment of a non-defended locality even where these conditions are not all satisfied.
6. An area loses its status as a non-defended locality when it ceases to fulfil the conditions described above or in an agreement between adverse parties to establish the non-defended locality. 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 456.1, 3–4 and 6.
In its chapter on land warfare, the manual further states in the context of siege warfare: “An assault against or bombardment of towns, villages, dwellings or buildings that are undefended is prohibited.” 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 614.1.
In its chapter entitled “War crimes, individual criminal liability and command responsibility”, the manual provides that “making non-defended localities … the object of attack” constitutes a grave breach of the 1977 Additional Protocol I. 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 1608.2.d.
Canada’s Geneva Conventions Act (1985), as amended in 2007, provides: “Every person who, whether within or outside Canada, commits a grave breach [of the 1977 Additional Protocol I] … is guilty of an indictable offence.” 
Canada, Geneva Conventions Act, 1985 as amended in 2007, Section 3(1).
Canada’s Crimes against Humanity and War Crimes Act (2000) provides that the war crimes defined in Article 8(2) of the 1998 ICC Statute are “crimes according to customary international law” and, as such, indictable offences under the Act. 
Canada, Crimes against Humanity and War Crimes Act, 2000, Section 4(1) and (4).
In 2013, in the Sapkota case, Canada’s Federal Court dismissed a request for review of a decision denying refugee protection to the applicant on grounds of complicity in crimes against humanity in Nepal between 1991 and 2009. While reviewing the submissions of the respondent, Canada’s Minister of Citizenship and Immigration, the Court stated: “The Respondent notes that the Rome Statute of the International Criminal Court … is endorsed in Canada as a source of customary law.” 
Canada, Federal Court, Sapkota case, Reasons for Judgment and Judgment, 15 July 2013, § 28.