Do you feel as if there's no end to their arguments and you don't know what to do? Take a look at your own behaviour: do you shout or argue with your partner in front of the children? Are you going through a period of major conflict? If this is the case, think about how you can improve you own situation.
Talk about your own problems with your children, without going into details they don't need to know. If they're aware of your problems, it might well help them understand your reactions and help them resolve their own arguments.