I noted some reporting via Twitter on the infighting in Southern Libya, but did not look further. Today this linked paper appeared and it opens with:
A multitude of armed groups and smuggling networks with transnational reach are driving southern Libya’s integration into the Sahel–Sahara region. Contrary to widespread external perceptions, the extremist presence remains a marginal phenomenon in the southwest (Fezzan), at least in relation to the political struggles. Rivalries over the control of borders, smuggling routes, oilfields, and cities, as well as conflicts regarding the citizenship status of entire communities, are of far greater significance. These conflicts are centred on southern Libya, but have a regional dimension because of the transnational links of the parties involved.
Link:http://www.smallarmssurvey.org/sana/...ispatch-3.html

There is a section on the Tuareg's too. Yet more to read.