Related Rule
Practice Relating to Rule 7. The Principle of Distinction between Civilian Objects and Military Objectives
Section B. Attacks against military objectives
Nigeria’s Military Manual (1994) provides: “Only military targets are to be attacked.” 
Nigeria, International Humanitarian Law (IHL), Directorate of Legal Services, Nigerian Army, 1994, p. 39, § 5(b); see also Nigeria, Code of Conduct for Combatants, “The Soldier’s Rules”, Nigerian Army, undated, § 2.
The Report on the Practice of Nigeria states that, during the Nigerian civil war, the Nigerian air force, in its raids against rebel enclaves, distinguished between military targets and civilian objects, bombing military targets while assiduously avoiding non-military targets. 
Report on the Practice of Nigeria, 1997, Chapter 1.3.