[souffle]

This is definitely a fight and the mark appear to be bite wounds. The first pic look like it might be infected? Keep them separate now as it is not a natural situation to keep two adults of the same sex together. It would never happen in the wild and they usually fight and can actually kill each other. The stress of living with a bully is also not good for their health. They should settle alone in around 10 days and be much more people friendly. Levels like you have there are not idea for dwarfies and they get territorial over the shelves and food bowls. Keep them alone and well apart with no access to each other. What bedding are you using? Is there soil in the cage? If the wounds don't heal in a week then see the vet. I hope they settle well.