Board Thread:General Discussion/@comment-36.73.46.45-20130728155312/@comment-6881629-20130728161825

Sometimes animals can see a crime and you get a bounty in the same menu as your journal there is a stat menu that will show past and present bounty. When the guards attack try blocking a few strikes and then put away you weapons that should yeild to them and you can then pay any bounty you have.

unfortunately it doesn't always work and if guards attack without warning (and your not a stage 4 Vampire without Dawnguard or in any beast form) it could be a bug. If it is the bug the only way i can tihnk of to stop them is give the city to the Imperials though the civil war or the main quest.