Règle correspondante
Practice Relating to Rule 156. Definition of War Crimes
Mexico’s IHL Guidelines (2009) states: “War crimes include … any … grave breach of the four Geneva Conventions of 12 August 1949.” 
Mexico, Cartilla de Derecho Internacional Humanitario, Ministry of National Defence, 2009, § 5.
In 2010, during a debate in the UN Security Council on children in armed conflict, Mexico’s Secretary of Foreign Affairs stated: “Serious violations of fundamental principles and norms of international humanitarian law are war crimes” 
Mexico, Statement by the Secretary of Foreign Affairs of Mexico before the UN Security Council, 6341th meeting, UN Doc. S/PV.6341, 16 June 2010, p. 13.