Ethiopia has refused to reverse its decision to withdraw its forces from Somalia by the end of the year, despite a plea from the African Union (AU) to delay the move which it fears may result in a security vacuum inside the country.

The government in Addis Ababa said last month that it would pull its troops out by the scheduled time amid fears the war-torn country could descend into further anarchy unless more peacekeepers are sent.

"We appeal to Ethiopia to consider phasing out withdrawal, until such time [when] more troops from Nigeria, Uganda and Burundi are deployed in Somalia," the Peace and Security Council (PSC) of the AU said in a statement at a meeting in the Ethiopian capital on Monday.

"The security situation in Somalia is alarming ... piracy is escalating against the background of weakening leadership and insurgents control nearly all the country with the exception of Mogadishu and Baidoa."

Rift

Abdullahi Yusuf's government is said to be on the brink of collapse [AP]

Adding to the fragility of Somalia's TFG government is a growing rift between Abdullahi Yusuf, the president, and Nur Hassan Hussein, the man he sacked as prime minister.

The AU and the US government have backed Hussein and have so far refused to recognise Mohamud Mohamed Guled, the new Somali prime minister, who was selected by the president.

The TFG is also facing an escalation in attacks from opposition fighters, that threatens to reach Mogadishu, the capital.

Fighters from al-Shabab, a group which split from the armed Union of Islamic Courts (UIC), have control of several town and cities across Somalia.

The opposition controls the south of Somalia and has launched a series of raids on Ethiopian forces which have tried to defend the government.

At least 10,000 civilians have been killed in two years of fighting, while a million people have been forced to flee their homes.