frat·ri·cid·al /ˌfrætrəˈsaɪdl◂/adjectiveadj [only before noun]
a fratricidal war or struggle is one in which people kill members of their own society or group 自相残杀的
Examples from the Corpus
fratricidal• 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.