African Union troops have come under attack as violence continues unabated in Somalia [EPA]
At least six Somalis have been killed and several wounded after fighting broke out between clans near the southern port town of Kismayo.
The AFP news agency reported that Friday's clashes erupted when one Somali army unit tried to expel another unit from a rival clan.
Colonel Abdi Hirre, commander of the Marehan clan unit, said: "Heavy fighting has broken out this morning.
"Our forces have gained the upper hand and we are defeating the renegade forces."
The fighting, between the Majerten and Marehan clans, broke out about 19km north of Kismayo, which is about 500km.
Hassan Mohamed Ali, a Marehan clan elder, said: "We have ejected criminals who were ambushing travelers from the Kismayo-Mogadishu road.
"We are still chasing them."
Mohamed Sheikh Aden, a witness, said: "I have seen two bodies and three injured people in Kismayo hospital. They were brought from the battlefield."
Capital blast
Meanwhile in Mogadishu, an army officer was killed and a second injured when their vehicle was hit by a roadside explosion, the latest in a string of attacks on government, African Union and Ethiopian troops.
Police fired shots in the air and made several arrests, witnesses said.
Violence has surged in Mogadishu since Somali government troops, backed by Ethiopian forces, ousted the Union of Islamic Courts group in April after months of fighting that left hundreds dead and hundreds of thousands displaced.
Somalia has been without a functioning central authority since the 1991 and the three-year-old transitional government has been unable to assert control.
