Fighting or frustrated?

The girls were doing the bunny 500 around their play area while I was doing some housework. All of a sudden I heard some real banging noise (I am used to this as they usually run into their penpanels). I looked over to see what was going on and the girls were chasing each other in a tight circle and there was fur everywhere.
I managed to separate them, and yelled for my OH who took his time to come down to help me and started complaining that I shouldn't yell so much, I almost started crying at that point :evil:

So I got them separate and checked them over, no injuries and as they are still moulting I have a lot of fur on me now. We decided to let them see each other (as this was the first time) and they bumped noses and then flopped next to each other and are sticking side by side now.
Am really confused :?

This is most definately fighting.

Are they neutered?
CAn they see or smell other rabbits?
Is one under the weather?

I was dreading that
No they aren't neutered yet, we spoke to our vet and were planning on doing it in August as they will be 6 months then, they are currently 3 almost 4 months old.
We only have the 2 so can't be other buns.

Currently keeping a very close eye on them as they have free range of the downstairs