Fighting has broken out between the Somali military and soldiers of the regional government of Jubaland.
Residents in the town of Bula Hawa – close to Somalia’s borders with Kenya and Ethiopia – say there have been exchanges of gunfire for several hours.
Tension between the government in the Somali capital, Mogadishu, and Jubaland officials has increased since last year’s disputed regional election.
In October, Jubaland’s security minister, Abdirashid Janan, was arrested and detained in Mogadishu after he was accused of committing human rights atrocities.
He escaped in January. The Somali authorities have been appealing to Kenya – which has forces in the area – to hand him over.