Civil wars have often occurred with war crimes (like killing non-combatants) with the purpose of performing ideology annihilation. At least one example is here https://en.m.wikipedia.org/wiki/Torre%C3%B3n_massacre

Creating distinct categories (ethnic cleansing or genocide etc.) of terrible things is an important exercise, but it can also dilute our overall understanding of human behaviors. The categories are useful for geological or historical analysis, but not for understanding baseline human behaviors.