Civilians continue to suffer from the mayhem in Mogadishu
At least nine people have been killed during fighting in the Somali capital, Mogadishu, where hungry crowds have looted trucks carrying food aid.
The unrest came as Somali pirates seized a Ukrainian ship reported to be carrying about 30 T-72 tanks.
In the capital, insurgents launched a surprise attack on Somali army posts and fighting took place near the palace of President Abdullahi Yusuf.
The palace is protected by government troops and their Ethiopian allies.
The fighting began on Thursday night when insurgents attacked the hill-top palace, sparking a gun battle and mortar exchanges, the BBC's Mohamed Olad Hassan reports from Mogadishu.
One resident said a mother and her three children were killed when a mortar landed on their house near the palace.
Three others people were killed by a separate mortar and two by stray bullets, witnesses said.
In a suburb of Mogadishu on Thursday, residents intercepted a World Food Programme convoy of more than 30 lorries carrying food aid destined for the drought-stricken southern region of Bakol, UN officials and witnesses said.
The UN estimates that more than three million Somalis are in urgent need of aid - a third of the population.
Somalia's government ousted Islamists from the central and southern part of the country in late 2006 with the help of forces from neighbouring Ethiopia.
Since then, Islamists have conducted a relentless insurgency against the government troops and their allies.
Our reporter says hardly a day goes by without violence, killings and explosions.
Meanwhile, the UN refugee agency says it is struggling to cope with the exodus of refugees from Somalia.
More than 1,000 refugees are arriving at camps in neighbouring Kenya every week, even though the country's border with Somalia is closed.
The BBC's Mark Doyle, who has recently visited the camps in Kenya, says some refugees do not even have a basic plastic sheet to protect them from the sun and the rain.
Recently, insurgents have directed attacks against a force of African Union peacekeepers - mainly Ugandan - who were first sent to Mogadishu 18 months ago.
In a press briefing on Friday in the Kenyan capital, Nairobi, the AU mission said the attacks were a calculated move to draw the peacekeepers into direct armed confrontation with the insurgents and make the force appear partisan.
"We regret all those attacks but we do not want to be drawn into the conflict," said Nicolas Bwakira, the AU special representative to Somalia.
"We are not there to fight, we are there to protect the civilian population, to protect institutions and to help delivery of assistance," he said.
The AU force also issued a statement saying that while it regretted civilian casualties, its peacekeepers would defend themselves from attacks.
Mr Bwakira said the force had sufficient capacity to respond to attacks from insurgents, and denied reports that the insurgency was getting stronger.