Related Rule
Cameroon
Practice Relating to Rule 42. Works and Installations Containing Dangerous Forces
Section B. Placement of military objectives near works and installations containing dangerous forces
Cameroon’s Instructor’s Manual (1992) states that installations containing dangerous forces “may be protected by weapons destined to ensure their defence in case of attack”. 
Cameroon, Droit international humanitaire et droit de la guerre, Manuel de l’instructeur en vigueur dans les Forces Armées, Présidence de la République, Ministère de la Défense, Etat-major des Armées, Troisième Division, Edition 1992, p. 20, § 226.
Cameroon’s Instructor’s Manual (2006) states:
352.2 – Special protection: (persons and objects specially protected.)
Certain categories of persons and objects benefit from special protection under the law of armed conflict and international humanitarian law, both in the civilian domain and in the military domain.
352.26 Installations containing dangerous forces
[Such installations refer] to dams, dykes and nuclear power stations whose destruction may lead to severe losses among the civilian population.
These installations may be protected by armaments just sufficient for fending off an attack. The immunity of these installations ceases when they are used in support [of military operations]. 
Cameroon, Droit des conflits armés et droit international humanitaire, Manuel de l’instructeur en vigueur dans les forces de défense, Ministère de la Défense, Présidence de la République, Etat-major des Armées, 2006, p. 92, § 352.2 and p. 94, § 352.26; see also p. 134, § 412.2 and p. 136, §412.26.