Règle correspondante
Practice Relating to Rule 22. The Principle of Precautions against the Effects of Attacks
Nigeria’s Military Manual (1994) states: “Similar to attack is the fact that defence measures which may affect civilian persons shall be announced in advance.” 
Nigeria, International Humanitarian Law (IHL), Directorate of Legal Services, Nigerian Army, 1994, p. 44, § 15.
According to the Report on the Practice of Nigeria, although no practice exists regarding precautions against the effects of attacks, the duty to take such precautions is a part of customary international law. 
Report on the Practice of Nigeria, 1997, Chapter 1.7.