30 August 2010 - Four African Union peacekeepers were killed when a mortar hit Somalia's presidential palace, officials say.

It is not clear if any Somalis were hit by the shells, fired as Islamist insurgents continue to battle government forces.

Those killed were from Uganda, one of just two countries to have sent troops to Somalia to help the government.

Last month, at least 76 people were killed in Uganda in bombings which a Somali group said it had carried out.

The battle for control of Mogadishu has intensified in the past week.

Last Monday, a suicide attack on a hotel killed at least 32 people, including six MPs.

The Islamist group al-Shabab said it had carried out the attack. Last month, al-Shabab said it was behind two bombings in the Ugandan capital, Kampala, in which more than 70 people died. 

Al-Shabab, which has links to al-Qaeda, controls much of southern and central Somalia, while the government - backed by the 6,000-strong African Union peace force - is confined to a few pockets of the capital.

A spokesman for the AU peacekeepers told the BBC the mortar attack was of little significance.

"These opposition groups fire from positions three to four kilometres from our positions. It was a pure coincidence that the mortar was able to kill four and injure eight of our soldiers," Major Barigye Bahoku said.

'Bluster'

He added that fears that al-Shabab fighters were going to close the road to Mogadishu's airport in their latest offensive were also unfounded.