I apologize for the awful screenshot. It was taken when I attempted to report this bug in-game, but failed due to an error.
Apparently, Bruma Rangers in Bruma will fight with guards at capture points, in my case Covenant Guards at the capture point near the Dark Anchor. They will fight endlessly. Bruma Rangers take no damage from guards, but the guards take damage from the Ranger (though manage to stay alive due to healing). This could be exploited if you are not of the same alliance as the guards.
Edited by SanderBuraas on 2 June 2018 10:06