Muslim on Muslim civil war in Yemen. Figures are from 2014 and doesn't include the earlier civil wars.
'According to UN estimates, the war has directly caused the death of over 3,000 children as of December 2020; while indirect causes of the war (lack of food, health and infrastructure) have led to additional deaths.[287]The UN estimates that at the end of 2021, 70% of all the casualties of the war (around 259,000) are children under five.[288]'