The battle in Kidal began Thursday afternoon and ended yesterday morning, said the UN officer who insisted on anonymity because he is not authorised to speak to the press.
The fighting was between the government-allied militia group, GATIA, and the Coordination of Azawad Movements, a coalition of groups seeking autonomy in northern Mali that includes ethnic Arabs and Tuaregs. The groups blamed each other for starting the violence.
Tuareg separatists took hold of Mali's north in 2012 before al-Qaida-linked extremists took control. French forces pushed them out of their strongholds in 2013. Since then, the north has remained on edge, with more than 11,000 United Nations soldiers and thousands of Malian troops maintaining an uneasy peace.