Siad Barre’s divide-and-rule policies intensified clan violence. [causal]
The only substantial difference, now, was that the volatile relations between these clan units across the whole country had been raised to fever pitch by the experience of Darod (particularly Marehan) hegemony and oppression, and the bitter fighting which, with modern weapons, wrought death and destruction on an unprecedented scale. The intensity of the ensuing 'clan cleansing' (as Somalis called it) in Mogadishu and elsewhere in the south had never been seen before. Siyad's policies of divide and rule, particularly since the Ogaden war, had included dispensing weapons to his current allies to fight his current foes, and this had facilitated the spread of modern arms throughout the country.
I.M. Lewis, I. M. Lewis, A Modern History of the Som…, loc. 615