Witnesses in Somalia's capital say at least 12 people have been killed in artillery battles between Ethiopian-backed government troops and Islamist insurgents.

Residents say the fighting began Sunday after insurgents attacked Ethiopian and Somali government soldiers as they tried to conduct raids in Mogadishu's Bakara Market.

Witnesses say most of the dead were civilians, killed by Ethiopian mortar shells fired into the market. 

The French news agency quotes a man as saying he saw the bodies of three Somali soldiers and one Islamist fighter in the nearby Hararyale neighborhood.

Bakara has been the scene of many battles during the 17-month Islamist insurgency.

The fighting has killed thousands of Somalis and driven more than a million from their homes.

The insurgency began in early 2007, soon after government and Ethiopian troops pushed an Islamist movement from power in Mogadishu and other Somali cities.

The United Nations recently initiated peace talks in Djibouti between the government and exiled Islamist leaders.  But a key Islamist opposition group has ruled out holding direct talks with the government until it sets a timetable for the withdrawal of Ethiopian troops.

Somalia has not had a stable central government in 17 years.

Some information for this report was provided by AFP, AP and Reuters.