At least five civilians died Thursday when Islamic insurgents attacked government soldiers near Mogadishu airport just minutes after Somali President Abdullahi Yusuf Ahmed took off, residents and officials said.
Heavy fighting followed the shelling, with Somali soldiers backed by Ugandan peacekeepers beating off the attack, witnesses said.
"Three people including a child died instantly after mortar shells landed in our village," Muhubo Isse, a resident in the area, told Deutsche Presse-Agentur dpa.
Hospital officials said five people had been brought in after the attack.
Major Bariyge Bahulko, a spokesman for the African Union peacekeeping mission in Somalia, confirmed the mortar attack on the airport, but denied that Ugandan troops took part in the fighting.
The attack came just days after the Somali government and some opposition figures signed a United Nations-brokered peace deal in neighbouring Djibouti.
The deal calls for a cessation of hostilities within 30 days, but the insurgents fighting the government have not signed up.
A similar attack took place at the start of June as Yusuf flew to Djibouti to meet UN officials there to back the peace talks.
The Horn of Africa nation has been in a state of anarchy since the overthrow of dictator Mohamed Siad Barre in 1991.
Fighting has intensified since transitional federal government troops and their Ethiopian allies wrested control of the capital Mogadishu from the Union of Islamic Courts (UIC).
The UIC brought relative order and curbed piracy during its six months in control in 2006.
Al-Shabaab, the UIC's armed wing, has been waging a guerrilla war ever since and hundreds of thousands have fled the vicious fighting in Modagishu to live in makeshift camps.