Non-Combatant Immunity - Principle of Distinction in Islamic Law.
This means that non-combatant enemies should not be attacked and any attack against helpless women, children, elderly etc is an act of aggression that angers the Almighty God.
The Prophet ﷺ’s principle of non-aggression not only prevents unjust wars from starting, it also prevents injustice from occurring once war has already been declared. We now turn our attention to how Islam established rules, based upon non-aggression, to minimize the harms of warfare as much as possible.
The old, the weak, [non-combatant] women, children, monks, laborers, and other civilians cannot be targeted unless they forfeit that immunity by fighting themselves.
Mutilation and torture are strictly prohibited.
For education:
What does Islam say about war and how it should be conducted? This publication covers the rules of engaging in war as outline in Islamic scholarly tradition.
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Compatibility between Modern IHL and Principles of Islamic Law of Conduct of War: A Comparative Analysis
The article explores the fact that the regulation of the behavior of combatants during an armed conflict has a very old Islamic history as compared to the modern-day IHL practices. Its acknowledgment of the notion of military necessity is emphatically conjoined with the observance of elementary considerations of humanity that are the sine qua non for mitigating the unnecessary harm to combatants on one hand and any harm at all to civilians on the other.