Witnesses say a barrage of artillery shells pounded the largest market in Somalia's capital, and a medical official says seven people were killed.
Pro-government forces have been waging an offensive against Islamist militants since February. The pro-government troops have captured several key positions so far.
Ambulance service chief Ali Muse said Wednesday that seven civilians died after shells hit Bakara market, and that 21 others were wounded.
Civilians in the Somali capital have suffered through two decades of violence, which started when the Horn of Africa nation descended into chaos in 1991.
Somalia's government said Tuesday that the offensive has made "remarkable" gains in the last few days.