وَإِن طائِفَتانِ مِنَ المُؤمِنينَ اقتَتَلوا فَأَصلِحوا بَينَهُما ۖ فَإِن بَغَت إِحداهُما عَلَى الأُخرىٰ فَقاتِلُوا الَّتي تَبغي حَتّىٰ تَفيءَ إِلىٰ أَمرِ اللَّهِ ۚ فَإِن فاءَت فَأَصلِحوا بَينَهُما بِالعَدلِ وَأَقسِطوا ۖ إِنَّ اللَّهَ يُحِبُّ المُقسِطينَ

If two groups of believers quarrel, reconcile them. But if one transgresses against the other, fight the one which oppresses until it complies with God’s command. Once it does, reconcile them justly and impartially. God loves those who are just.