Related Rule
El Salvador
Practice Relating to Rule 6. Civilians’ Loss of Protection from Attack
El Salvador’s Soldiers’ Manual states that combatants must “never attack … women, children, the elderly or any person who does not bear arms”. 
El Salvador, Manual del Combatiente, undated, p. 3.
During the conflict in El Salvador, the armed forces reportedly attacked on numerous occasions what the guerrillas called “the masses”, i.e. parts of the civilian population who did not use arms or resort to violence but who were believed to sympathize or collaborate with the FMLN and who lived in zones of guerrilla resistance or in conflict zones. 
“La cuestión de las masas”, Estudios Centroamericanos, Universidad Centroamericana José Simeón Cañas, Vol. XLII, No. 465, July 1987, pp. 414–434.