Many Somalis resent the presence of the Ethiopian troops
Ethiopian troops have started to prepare to leave Somalia on the day they were supposed to complete their withdrawal, witnesses say.
The troops were packing mattresses, personal belongings and loading trucks with military supplies, they said.
But there was no sign that the Ethiopians had started to leave the capital Mogadishu, as they have promised to do by the end of the year.
Some fear the Ethiopian withdrawal could lead to a power vacuum.
But others say it could make it easier for a new government to be formed, including moderate Islamist forces.
The Ethiopian intervention to help government forces oust Islamists from the capital two years ago was deeply unpopular with many Somalis.
Various Islamist and nationalist groups now control much of southern Somalia. Government forces only control parts of Mogadishu and the town of Baidoa.
But hardline Islamist leader Sheik Muktar Robow said his forces would continue to fight government troops even after the Ethiopian troops leave.
"We will not stop fighting even if the Ethiopian troops withdraw because our aim is to implement Islamic law across Somalia," he said.
President Abdullahi Yusuf this week resigned after a power-struggle with his prime minister, partly over whether to negotiate with moderate Islamists.