Two of Somalia's faction leaders have become embroiled in fierce fighting in the capital, Mogadishu.
Much of Mogadishu is in ruins after years of fighting
Gunmen loyal to Mohammed Dhere and Musa Sudi Yalahow have exchanged fire in what began as an argument between groups of armed guards.
Four days of clashes have left at least 20 people dead in some of the worst fighting Mogadishu has seen in years.
Somalia has not had an effective central government since 1991 and armed factions often fight over territory.
Witnesses said heavy machine guns, rocket-propelled grenades and anti- aircraft missiles were being used.
Many residents were seen fleeing their homes in the northern neighbourhood of Abdul Aziz where the fighting has been taking place.
Hospital staff said more than 70 people were injured.
Most of Somalia's warlords last year signed a ceasefire at peace talks in neighbouring Kenya.