My males became temporarily more aggressive after neutering. My females have episodes where they seem more vicious, but i think it's harmless. Have you checked for any actual wounds? As long as there is no open wounds or signs of any real damage, i'm sure they will settle.
If they are around new bunnies, it can be that. If mine don't have covers on the sides of the runs, they aggrevate each other, they will chase alot more and get abit nasty if they can see each other. Scent doesn't cause so many problems if they are far enough away from each other, but definately sight. They get very territorial. Maybe that's why they are fighting because of the others.