Often you may find the team tries to draw you into the conflict. My strategy is to first push it back on them to resolve their own issues. If that doesn't work (I find it often does since I appear to be not taking side and getting drawn in) and they return to me for resolution, I patiently listen to both sides and then facilitate developing a plan they can agree on to resolve the problem. Mediation is very similar to negotiation in this respect. Unlike either, I have a vested interest in getting this resolved, so if they can't agree, we will agree to disagree and set some boundaries on what appropriate behaviors will be going forward.