Fighting between rival factions in Mogadishu killed at least 16 people as chaos engulfed the Somali capital and spurred the war-torn country's neighbours into action, officials said on Tuesday.
Most of the latest victims were combatants killed in several incidents on Monday, as Islamist insurgents continued to close in on the shrivelling perimeter controlled by the government but also fought among themselves.
"Violent elements attacked government forces in northern Mogadishu, sparking heavy fighting. They were defeated and several of their fighters were killed," government security officer Mohamed Abdirahman told AFP.
"Two of our soldiers were also killed as well as three civilians who were caught in the crossfire," he added.
Insurgents have been harassing government forces in northeastern districts lately to seize positions from which they can target bases of the African Union mission in Somalia (AMISOM) and disrupt their supplies by striking the seaport.
Rebels from the Al Qaeda-inspired Shebab movement and the Hezb al-Islam group in May 2009 launched a major offencive which President Sharif Sheikh Ahmed's forces and his AMISOM protectors have been unable to repel.
Ali Muse, the head of Mogadishu's ambulance services, also told AFP that three other civilians, including two from the same family, were killed when an artillery shell smashed into their home in Halimoheyte district.
In a separate incident in the southern Labadhagah neighbourhood, six Hezb al-Islam militants, including one of the group's top commanders, were mowed down when gunmen in a minivan intercepted their vehicle, witnesses said.
Minutes later, two Shebab fighters were killed outside a nearby mosque where the group's top leaders usually preach, in an apparent retaliation for the earlier executions.