Five people were killed and more than 50 injured in heavy exchange of fire between Islamic insurgents and security forces in the Somali capital, officials said.
The government forces were backed by the UN peacekeepers in the latest fighting to wrest control of the areas ruled by militants in Mogadishu.
The shells hit the residential areas in Heliwaa district, killing at least five civilians, local residents said.
"So far we have taken 51 wounded people to hospitals and we think the figure may rise because the ambulances are still picking injured people from other parts of the city," Ali Muse, head of a local emergency service told Xinhua.
The latest fighting erupts after weeks of verbal sparring between the Somali government and militants.