Règle correspondante
South Africa
Practice Relating to Rule 53. Starvation as a Method of Warfare
Section C. Blockades and embargoes that cause starvation
South Africa’s LOAC Teaching Manual (2008) states:
4.1 LOAC [law of armed conflict] in Naval Warfare
- The declaration or establishment of a blockade is prohibited if it has the sole purpose of starving the civilian population or denying it other objects essential for its survival or the damage to the civilian population is, or may be expected to be, excessive in relation to the concrete and direct military advantage anticipated from the blockade. 
South Africa, Advanced Law of Armed Conflict Teaching Manual, School of Military Justice, 1 April 2008, as amended to 25 October 2013, Learning Unit 4, pp. 198 and 206.