Règle correspondante
Practice Relating to Rule 1. The Principle of Distinction between Civilians and Combatants
Section B. Attacks against combatants
Indonesia’s Air Force Manual (1990) states that a person who is not a member of the armed forces nor a member of a militia but participates in the hostilities is an unlawful combatant and is considered a military objective. 
Indonesia, The Basics of International Humanitarian Law in Air Warfare, Indonesian Air Force, 1990, §§ 22–23.