Violence flared in Mogadishu, and areas south of the city, as warlord gunmen fought each other over control of territory. Nearly fifty people have been killed and over 80 wounded. Heavy machineguns and mortars were used.
The gunmen survive by running extortion and protection scams. Businesses survive by paying a gang to keep all the other gangs away. But some gangs get greedy and try and take control of a neighborhood or stretch of highway away from another warlord. This almost always results in a gun battle, followed by some negotiation and, perhaps, an adjustment of boundaries.
There are over 100,000 of these gunmen in the country, working for dozens of warlords. Mogadishu alone has over 60,000 gunmen (for a city of about one million people.) But this is because the city is a major port and the largest urban area in the country. There's more money in Mogadishu, which attracts more guys with guns.