Somalia's government said it has repulsed a military attack by foreign-backed insurgents trying to overrun the presidential compound in Mogadishu and oust President Sheikh Sharif Sheikh Ahmed. News agencies report at least 110 people, mostly civilians, have been killed in three days of fighting. The African Union has secured pledges of two additional troop battalions to re-inforce its Somalia peacekeeping mission.

Somalia Defense Minister Mohamed Abdi Gandhi said security forces beat back an attempted coup by a combined force of domestic and foreign fighters in a series of battles during the past few days in the streets of Mogadishu.  

Gandhi briefed a closed-door meeting of the Somalia consultative group at African Union headquarters.

Reports from Mogadishu indicate sporadic fighting was continuing.

Forces allied with the insurgent group al-Shabab control much of Mogadishu. The government controls a few square kilometers of the city, aided by a force of about 4,000 troops from the AU peacekeeping mission AMISOM.

AU Peace and Security Commissioner Ramtane Lamamra said the attacking force, backed by nearby Eritrea, came from outside the city and was trying to capture Villa Somalia, the presidential palace.

"The attack was defeated, the Shabab and Hezb-i-Islami did not succeed in getting near the Villa Somalia or getting near the positions of AMISOM," he said.

Lamamra also said Sierra Leone and Burundi have each agreed to send an additional battalion to bolster AMISOM. The mission is at just over half its authorized strength of 8,000, and the two new battalions will bring it up to about 6,000. Lamamra refused to say when the troops would arrive.

"This is an information we are not going to share with the Shabab, through the media," he said.

Lamamra and others attending the meeting expressed frustration at what they called false and misleading media reports coming from Mogadishu, many suggesting a deepening spiral of violence, the impending fall of Sheikh Sharif 's fragile government and the rise of hardline Islamic rule.

U.N. special envoy Ahmedou Ould Abdallah scoffed at the widely-held belief the conflict is motivated by religious or political differences. To reporters, he said the insurgents are mostly clan factions trying to protect criminal business interests built up during the nearly two decades Somalia has been without effective government.

"We should not be taken hostage by all this is Islamist or non-Islamist. There is also a clear agenda of criminal economic activities. How many private airports do we have in Somalia?" He asked. "How many private ports? We see only a political crisis. To perpetuate the idea that it is a civil conflict for political or religious reasons is very easy. After 20 years people are seeing how many illegal clandestine imports, clandestine exports, money laundering and piracy has been very helpful in drawing attention to the money side of this crisis," he said.

Somalia will be among the top issues on the agenda Saturday when the U.N. Security Council convenes a joint meeting in Addis Ababa with the AU Peace and Security Council.

The international donor community pledged $213 million to help stabilize Somalia at a conference in Brussels last month. But the latest fighting has prompted another mass exodus of refugees from Mogadishu, and raised doubts among donors about whether the Horn of Africa nation can recover after so many years of anarchy.