MOGADISHU, Somalia — Ethiopia handed over security duties Tuesday to a Somali force, raising fears that the Horn of Africa country — already fighting an Islamic insurgency and rampant piracy — could collapse into chaos if extremists with alleged al-Qaida links move to seize power.

The Ethiopian pullout after a two-year deployment was widely welcomed by Somalis who had viewed the troops as an occupying force, but the Ethiopians also have provided a measure of stability in a land plagued by extreme poverty and relentless warfare.

Few expect the Somali government can ensure security even with the help of the Islamist faction with which it has agreed to share power. The government controls only pockets of the capital, Mogadishu, and Baidoa, where parliament sits — and has tried to rule without a president for weeks.

It was unclear when all the thousands of Ethiopians will have departed. They were pulling out in stages and gave no exact dates for security reasons.

"It is time Somalia stands on its own feet," said Ethiopian commander Col. Gabre Yohannes Abate, as he handed over security operations during a ceremony at the presidential palace in Mogadishu. "So we are saying goodbye to all Somalis and their dignitaries."

An African Union peacekeeping force of about 2,600 remains in Somalia, where it is limited to guarding the seaport, the capital's main airport and government buildings, all in Mogadishu. The United States this week circulated a draft resolution at the United Nations calling for a U.N. peacekeeping force to be deployed to replace the A.U. force.

Fears of a power vacuum have been balanced by the hope that the Ethiopian withdrawal will soothe festering hatreds: The foreign troops have been a rallying cry for the insurgents to gain recruits even as the militants' strict form of Islam has terrified people into submission.

"The insurgents have been fighting for the withdrawal of Ethiopians all this time," Prime Minister Nur Hassan Hussein said during the hand-over. "When the Ethiopians have begun withdrawing, there is no need for fighting again. I urge all Somalis to become peace-loving people."

Somalia has not had a functioning government since warlords overthrew a dictator in 1991 and then turned on each other. Its weak U.N.-backed government called in the Ethiopian troops in December 2006 to oust an umbrella Islamic group — which included the al-Shabab extremists at the center of the current fighting — that had controlled southern Somalia and the capital for six months.