At least five Somalian soldiers were killed in an attack on their base by Al Shabab militants in Kismayo.
Some of the soldiers were beheaded after the militants briefly took control of the camp, witnesses told AFP.
Last week over 50 Burundian peacekeepers from the African Union were killed in an attack by the militant group.
The African Union Mission in Somalia (Amisom) has more than 20,000 troops in the country, but is now withdrawing from some of its smaller outposts in southern Somalia, residents have told the BBC Somali service.