Rival militias have for weeks been preparing to fight for Somalia's main southern trading centre, Kismayo port.
The latest fighting broke out this week at Bulo Haji, about 100 kms south of the port and in the nearby Hosingo districts of lower Jubba region of south Somalia.
The clashes flared after militia from the Juba Valley Alliance (JVA), which controls Kismayo and surrounding areas, attacked the bases of a rival militia leader - General Morgan, his spokesman told local media.
Hundreds of militiamen and several vehicles mounted with machine guns deployed by warlord Muhammad Said Hersi, known as General Morgan, have based themselves at Bulo Haji.
Talks on to forge new national
government in Somalia
The unnamed spokesman said General Morgan's militia lost more than six fighters while nine others were wounded, and that his group had killed a large number of the JVA militia, and arrested 14 of them, including the leader of the attack.
The spokesman added that his forces torched two armed battle wagons and seized another one at Bulo Haji town.
Media reports said General Morgan had been wounded during a battle at Abdalla Birole village, 45km outside of Kismayo town, but there was no confirmation of the claim.
Nine people, about half of them JVA fighters and the rest civilians, were killed in this clash, the independent Kismayo FM radio reported.
A spokesman for the JVA confirmed the fighting, but blamed General Morgan's militia for initiating it.
"We are ready for whatever kind of fighting it takes to keep it"
"We are defending our territory from those who are trying to seize it, they will not succeed," the JVA spokesman, who declined to be named, said from Kismayo.
"We are ready for whatever kind of fighting it takes to keep it."
Morgan captured Kismayo in 2001 but was ejected within days by the JVA, a militia coalition which also drove him out of the town in 1999, ending his six-year control of the town.
Kismayo, 500 kms south of the capital Mogadishu, is the main trading centre for southern Somalia, hosting a market for food grown in the nearby fertile Juba Valley.
Kismayo residents worry about the impact the clashes could have on ongoing talks to forge a new national government.
Somalia has been torn by war since the overthrow of military ruler Muhammad Siad Barri in 1991 and warlords have carved the country up into warring fiefdoms.