Соответствующая норма
Peru
Practice Relating to Rule 70. Weapons of a Nature to Cause Superfluous Injury or Unnecessary Suffering
Peru’s IHL Manual (2004) states: “It is prohibited to use weapons that can … cause superfluous injury or unnecessary suffering.” 
Peru, Manual de Derecho Internacional Humanitario para las Fuerzas Armadas, Resolución Ministerial Nº 1394-2004-DE/CCFFAA/CDIH-FFAA, Lima, 1 December 2004, § 26.e.(1); see also §§ 27.c.(2).(a) and 31.(b).(1).(a).
The manual also states: “Causing unnecessary suffering and superfluous injury is prohibited and should be avoided. All forms of violence that are not absolutely necessary to gain an advantage over the enemy are also prohibited.” 
Peru, Manual de Derecho Internacional Humanitario para las Fuerzas Armadas, Resolución Ministerial Nº 1394-2004-DE/CCFFAA/CDIH-FFAA, Lima, 1 December 2004, § 27.a.(1).
Peru’s IHL and Human Rights Manual (2010) states: “It is prohibited to use weapons that can … cause superfluous injury or unnecessary suffering.” 
Peru, Manual de Derecho Internacional Humanitario y Derechos Humanos para las Fuerzas Armadas, Resolución Ministerial No. 049-2010/DE/VPD, Lima, 21 May 2010, § 27(e)(1), p. 236; see § 27(2), p. 236; § 28(d), p. 43 and § 154(b)(1), p. 338 and § 2(a), p. 360.
The manual also states: “Causing unnecessary suffering or superfluous injury is prohibited and should be avoided. All forms of violence that are not absolutely necessary to gain an advantage over the enemy are also prohibited.” 
Peru, Manual de Derecho Internacional Humanitario y Derechos Humanos para las Fuerzas Armadas, Resolución Ministerial No. 049-2010/DE/VPD, Lima, 21 May 2010, § 28(a)(1), p. 237.
Peru’s Decree on the Use of Force by the Armed Forces (2010) states:
The following principles are recognized by the norms of international humanitarian law as applying before, during and after the use of force:
c. Limitation. … International humanitarian law prohibits the use of means and methods of using force which may cause unnecessary suffering or harm. 
Peru, Decree on the Use of Force by the Armed Forces, 2010, Article 7(d).
In a statement at the First Review Conference of States Parties to the Certain Conventional Weapons in 1995, Peru declared that it “shared the international community’s concern at the increasing use of certain conventional weapons, including anti-personnel landmines, whose devastating effects on the civilian population had been well documented”. It added that “the Review Conference was duty bound to bring an end to the humanitarian crisis caused by such weapons”. 
Peru, Statement at the First Review Conference of the States Parties to the Convention on Certain Conventional Weapons, Vienna, 25 September–13 October 1995, UN Doc. CCW/CONF.I/SR.5, 3 October 1995, §§ 67–69.