Somalian Prime Minister Ali Mohamed Gedi has ordered all Somalis - including the country's war lords - to turn in all of their weapons within the next three days.
Mr. Gedi said at a news conference Monday in Mogadishu that people will have three days from Tuesday to voluntarily surrender their weapons. He says, after that, the government will collect them by force.
The prime minister also offered amnesty to retreating Islamist fighters if they turned themselves in to authorities.
Islamist fighters have been withdrawing from their strongholds, including the capital, Mogadishu, for more than a week since Ethiopia entered the war against Islamic militants.
They withdrew from their final southern stronghold - the port city of Kismayo - early Monday to escape advancing Ethiopian-backed Somali forces. Most of the militants are reported to be fleeing toward other port cities and the Kenyan border.
Hardline Islamist leaders confirm the Kismayo retreat, but vowed to fight on.
The Islamists declared a "holy war" on Ethiopia because of its support for Somalia's U.N.-backed interim government.
Somalia has been without an effective central government since 1991, when warlords overthrew dictator Mohamed Siad Barre. A U.N. backed interim government has been struggling to hold power.
Fighters loyal to Somalia's Islamist Courts movement began seizing control of Somalia several months ago, saying they were restoring order.
Some information for this report provided by AP, AFP and Reuters.