Elder Scrolls 4 : Oblivion question ?

I am currently doing the mages guild quest-line, and i am now doing missions for Hannibal Travern, the Arch - Mage . I was told to go and see the count of Skingrad , and he told me to find and kill the vampires in bloodcrust cave and the vampire hunters around the town . I went to bloodcrust first , and wiped out the vampires on my own. Now I have a problem, I can't seem to kill the vampire hunters without most of the city guard running at me . I was planning on running into the town , using a save I made after leaving bloodcrust , and killing all the hunters quickly . This would put a 6,000 bounty on my head , so i should go to jail . But will going to jail throw me out of the mages guild ? All help appreciated :D