The Somali army is backed by Ethiopian heavy weaponry
Somalia's Ethiopian-backed government says it controls the southern port city of Kismayo - which was the last stronghold of Islamist militiamen.
The Islamists retreated as the army, supported by Ethiopian aircraft, tanks and artillery advanced on the city.
The Somali prime minister urged the African Union to send peacekeepers and offered an amnesty to Islamic fighters.
The Islamists had swept through Somalia last year, and their retreat from Kismayo is seen as a major reversal.
Somali Prime Minister Ali Mohamed Ghedi told AFP news agency: "Kismayo is already in the hands of the government. The Islamists have run away."