Heavy fighting broke out in Mogadishu on Friday as Somali government and African Union troops battled a powerful militia warlord in a bid to disarm him, security officials said, reporting a number of casualties.
"Government forces and African troops are conducting security operations in Mogadishu, and this morning militiamen confronted them," government security official Mohamed Yusuf said.
Bursts of gunfire and heavy explosions were reported before dawn, with witnesses reporting at least five dead.
Rocket-propelled grenades were fired by both sides, witnesses said.
Somalia's government launched a disarmament campaign earlier this month, with troops backed by the AU mission in Somalia (Amisom) on Friday fighting to seize weapons from militia leader Ahmed Dai.
Government troops said they had taken control after several hours of fierce battle.
"Forces are continuing with their operations," Mr Yusuf said, saying that while there were casualties, he was unable to confirm details.
Witnesses said they saw the bodies of several killed including civilians.
"Fighting was very heavy, both sides used heavy machine guns and fired grenades. I saw the dead bodies of five people, three of them civilians, but now the fighting seems to be over," said Abidiweli Mohamed, a local resident.
Ali Lugey said he saw AU and government solders "storming the house" of Dai, who commands his own well-armed militia.
"I saw several casualties, dead bodies and children who had been injured in the crossfire," Mr Lugey said.
But militia commander Dai told reporters the only guns he had were for "self-defence."
"Amisom and security forces raided my house early this morning and we defended ourselves," Mr Dai said, saying several people had died, but without giving a precise toll.
"If they are claiming the operation is aimed for disarmament, then I have got no weapons, except a few for self-defence purposes," he said.
Mr Dai is based in the capital's Madina district, a neighbourhood close to the heavily defended airport zonet, the headquarters of the 22,000-strong AU force.
Mr Dai's militia opened fire and a "firefight ensued," Amisom said, adding that the "militia was overpowered and 20 were arrested".
Mr Dai himself was not captured.
War-torn Somalia is awash with guns after more than two decades of conflict, with several politicians and local leaders commanding what are effectively private armies.
Such forces are not connected to Somalia's hardline Al-Shabaab Islamists, which are fighting to topple the internationally backed government.
The clashes come just two days after UN Security Council envoys briefly visited a fortified zone within the dangerous capital, where they promised to support the first elections in decades, scheduled for 2016.