|When your co-workers would rather punch each other than punch a time clock, this is an issue that needs to be discussed with your manager. There is a real problem in your department, and any rational manager would like to know about it.
It sounds like you are overly concerned about being branded as a corporate crier if you go to management. If it makes you more comfortable, you can certainly try to intervene and resolve the problem yourself, but remember that the battle can easily move from two combatants to three.
The better option is for you to join forces with several of your fellow employees and then meet with your manager. After all, your co-workers sound like they are as upset with the war zone as you are.
At the core of the problem is the fact that your manager is away from the office frequently. Since the main responsibilities of a manager are to manage, this is not easily accomplished from afar. When a manager is missing, the result is mismanagement.
In your meeting with the manager, you can approach the problem of the battling employees in the same way that you would discuss any other matter that is interfering with your ability to do your job. However, your less obvious message is that your department needs more regular supervision, either by the manager or by someone acting in his or her behalf.
At present, it sounds like no one has been designated as assistant manager or acting manager, or somebody has dropped the ball. It will be important for your manager to be sure that someone is formally empowered in an acting leadership role, with full authority to oversee the department during the manager's absence.
The warring employees in your department already know how to get along -- they do it whenever the manager is present. If they can act this well in front of a manager, their performance should be even more compelling in front of an acting manager.