Whatever strategies a teacher uses to resolve conflict in the classroom, there needs to be consistency. Without consistency, no strategy will work. With that said, let me suggestion a few ways in which to help with conflict resolution.
First, the teacher should model tolerance and openness to new ideas and differing view points. This simple approach will do wonders for students.
Second, you can have students talk out and express their differences. To vocalize potential conflicts can do wonders. And if a teacher acts as a mediator, he or she can help people to see different perspectives. This, in turn, can cause people to be more embracing of each other.
Third, if these fail, the teacher can bring in a high authority - the principal and the parents of the children.