fratricidal
From Longman Dictionary of Contemporary Englishfratricidalfrat‧ri‧cid‧al /ˌfrætrəˈsaɪdl◂/ adjective [only before noun] a fratricidal war or struggle is one in which people kill members of their own society or groupExamples from the Corpusfratricidal• That apart, I would hesitate to enter the traditional fratricidal debate between Edinburgh and Glasgow.• In opposition, the fratricidal strife within the Labour Party became stronger.