Nine Somali civilians were killed in the capital Mogadishu, where Islamist insurgents are battling African Union peacekeepers and Ethiopia-backed government troops, witnesses said.
   
Four civilians were killed after insurgents fired mortar shells at Mogadishu's main airport, where the Islamists have sought to impose a ban on planes landing.
   
"One mortar shell struck a building where some people were washing second-hand clothes. Four civilians, including a woman died and five others were injured," said witness Hassan Muktar Anteno.
   
Four others were killed when another mortar hit a civilian target.
   
"Four died in front of my shop as people were busy buying gifts for the (Ramadan) festival," said Mohamed Ali Nur, a trader.
   
Another mortar shell struck on a civilian bus near south Mogadishu's Bakara intersection, leaving one dead and wounding eight others.
   
Somalia's Al-Shebab movement earlier this week warned that all flights should cease as of September 16, arguing that the airport was an instrument of Ethiopia's military occupation of Somalia.
   
Bahuko Paridgye, spokesman for the African Union forces, said the mortars were fired at the airport when a plane carrying supplies for troops landed on Saturday.
   
With war-torn Somalia's roads dotted with rogue checkpoints and freelance gunmen and its waters infested with pirates, traders have warned the airport's closure would only further stifle the troubled nation's economy.
   
An AU statement Saturday said attacks on its forces "constitute a breach of international law and a further threat to international peace and security." The body repeated calls for the UN Security Council to deploy a peacekeeping operation to the lawless east African country.