blue-on-blue
adjective [ before noun ] military specialized uk/ˌbluː.ɒnˈbluː/ us/ˌbluː.ɑːnˈbluː/
（战争中）误伤己方的
relating to an attack in which soldiers, etc. are injured or killed by their own army or by soldiers on the same side as them
The number of blue-on-blue deaths has risen steadily during the present campaign. 在当前的战斗中，由于己方误伤导致的死亡人数持续上升。
Compare: friendly fire