Rival clans in southern Somalia have clashed in a fight for control over a trading town, and witnesses report dozens of deaths and injuries.

Residents say more than 20 people were killed and 30 injured in the battle that began late Friday night in a town identified by Reuters news agency as Ceel Waaq near the Kenyan border.

The town is described as a center of commercial activity.

Warlords have ruled Somalia since dictator Mohamed Siad Barre was ousted in 1991.

Some information for this report provided by AP and Reuters.