At least 10 people were killed on Saturday in fresh fighting between militias loyal to rival self-declared leaders in the key Somali port city of Kismayo, dpa reported.
Six civilians were among the dead, government officials said. Some 20 people were wounded in the battles. On Friday, at least six people were killed.
Residents say the violence is the worst the city has witnessed since Kenyan troops and a government-allied militia pushed out the Islamist al-Shabaab rebels in October.
The African Union's mission in the Horn of Africa nation, meant to help the weak central government build control in the war-torn country, remains in charge of security in the city.
Residents said there was as yet no sign the AU force was moving to intervene in the fresh clashes.
Public transport, schools and businesses in many parts of the city were closed for a second day.
The Kismayo port is a key source of revenue. Losing the city was a blow for al-Shabaab, which has been ceding ground to the AU and government forces in recent years.
The Islamist group still holds sway in many rural areas in the centre and south of the country.
Powerful figures in the Kismayo region are now feuding over the profits from the port and nearby agricultural lands, sparking the latest clashes.