Make sure that both of your male cats are neutered. If you do not get a male cat fixed he can become more aggressive over time and will start to mark his territory. Separate the cats if need be. Lock them in separate rooms when you're not home to watch them.
Well the best thing to do is to have the two male cats fixed. This should calm the aggressiveness alot as they are probably doing this over territory issues. If your cats are all ready fixed then I would seperate them for a while kinda of like time outs.