If two parties of believers fall to fighting, what will be the responsibility of other believers?

 

Verse 9 of Chapter 49

And if two parties among the believers fall to fighting, then make peace between them both. But if one of them outrages against the other, then fight you (all) against the one that which outrages till it complies with the command of Allah. Then if it complies, then make reconciliation between them justly, and be equitable. Verily, Allah loves those who are the equitable.