Prime Minister Ali Mohamed Gedi said allied Somali-Ethiopian troops were searching former insurgent strongholds and targeting looters in the shell-scarred seaside city.
"Now Somalia has law and order, Mogadishu residents should surrender all weapons to the government," he told reporters. "We are calling on all Mogadishu residents to take part in securing the capital."
His administration earlier appointed two former warlords to key positions as it seeks to impose its authority after Mogadishu's heaviest fighting in 16 years.
Abdi Hassan Awale, popularly known as Qaybdiid, and Mohamed Dheere take over as national police boss and mayor of the gun-infested capital respectively.
More than a third of the city's one million residents have fled the battles, which pitted government troops and their Ethiopian military allies against Islamist insurgents, foreign jihadists and some clan militia.
Qaybdiid was one of the last of a group of U.S.-backed warlords to surrender to Islamists who seized the capital last year before being ousted by the allied Somali-Ethiopian troops.
Dheere was the self-appointed local governor whose forces secured Jowhar, 90 km (55 miles) north of Mogadishu, as a temporary base for the interim government in 2005, after it was born out of tortuous peace talks in neighbouring Kenya.
"We wanted to do some reshuffling due to the factors on the ground," a spokesman for President Abdullahi Yusuf told Reuters, without elaborating. "We are hoping they will both fulfil their jobs well and do something about public health."
Both men inherit huge challenges. While the guns largely fell silent on Friday, it remained unclear whether the insurgents had been defeated or melted away to regroup.
Some homes and commercial properties have been looted.
The United Nations has warned of a looming catastrophe with more than 365,000 people fleeing the capital since February -- most of them clinging to survival in surrounding areas already ravaged by a severe drought and then swamped by floods.
It says the displacement rate in Somalia over the past three months has been worse than in Iraq in the same period.
The African Union (AU) wants more peacekeepers sent urgently to support a vanguard of about 1,500 Ugandan troops -- who have so far been restricted to guarding sites like Yusuf's office and the air and sea ports, and to treating wounded civilians.
Several African nations have pledged to send soldiers, but as with its previous peacekeeping foray in Sudan's Darfur region, the AU is facing shortages of money and equipment.
- Reuters - Thomson Reuters Foundation
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