How to re introduce male Roborovski hamsters?

[Roborovski hamster]

Hi, recently I acquired a pair of male Roborovski hamsters, one wild and one white face. I have two wild females, and one female white face. So I paired them off, I got them on the 16th of May, but since I put them together everyday, on the 2nd-3rd day they starting fighting! I mean, proper fighting. And in a second one of the males had a bleeding leg! They were in a very tight circle and were biting each other. They also bit me a couple times whilst a broke it up-____-

How can I re introduce? I've tried using bars, but they still try get at each other, or do I just need to face that I can't keep them together anymore? Oh and this happened with my two females. Biscuit and Poppy. Poppy (Biscuits daughter) escaped, for 8 days, and when I put them back together they started fighting, nothing serious though.

Thanks!
Oh, and I've tried mutual territory thing, it doesn't work. Do you think they are just protecting they're females? Oh and in my picture, there is Cloud and Cookie, my two white faced robo's^^

 

[Jessica]

Wow ok. In my opinion i would not reintroduce them. That fight sounds very serious and i highly doubt it was over females. Male mice have been know to fight to the death and i can only imagine (if there was already blood from one fight) that hamster's will do the same. As for poppy and her mother fighting i would say that's more of a argument over territory .

Your hamsters are very beautiful i also have a pic of 3 of my fancy mice Mishka. Kawai, and Nipper.
Good luck and i hope everything works out.