Inside Story - Libya's power struggle

The protests in Libya are continuing and Muammar Gaddafi, the Libyan leader, is struggling to hold on to power. Major parts of the country are under the control of pro-reform protesters. Many now are fearing a violent showdown. But in a country divided by tribes, alliances and clans, it is difficult to draw the outlines of a future battle. Who exactly are the groups that are holding the future of the country in their hands? And how long can the Libyan leader survive?