Three Somali soldiers lost their lives in clashes between al-Shabab fighters and transitional government troops on 30th Street in Mogadishu on Saturday.
Ten government soldiers also sustained injuries, the Press TV correspondent in Mogadishu reported.
Also, two civilians were killed and four others suffered injuries as the two sides exchanged heavy fire with assault weapons and barrages of mortar shells were fired.
In a separate incident, 15 people lost their lives and 20 others were wounded on Saturday when al-Shabab fighters turned on members of the rival Ahlu Sunna Waljama'a group and clashed with them in northern Mogadishu.
Somalia has not had a functioning government since 1991, when warlords overthrew former dictator Mohamed Siad Barre.
Over the past two decades, up to one million people have lost their lives in the fighting between rival factions and due to famine and disease.
There are more than 1.4 million internally displaced people (IDPs) in Somalia. More than 300,000 IDPs are sheltering in Mogadishu alone.
Most of the displaced live in poor and degrading conditions on makeshift sites in southern and central Somalia, according to the United Nations High Commissioner for Refugees.