Соответствующая норма
Nigeria
Practice Relating to Rule 20. Advance Warning
Nigeria’s Military Manual (1994) provides: “Where the tactical situation permits, effective advance warning shall be given of attacks which may affect [the] civilian population. This could be done by warning shots or discharge of leaflets from an aircraft.” 
Nigeria, International Humanitarian Law (IHL), Directorate of Legal Services, Nigerian Army, 1994, p. 44, § 14; see also p. 45, § 16(c) and The Laws of War, by Lt. Col. L. Ode PSC, Nigerian Army, Lagos, undated, § 13.