MOGADISHU, Somalia (AP) -- Gunfire and mortar shells rocked Somalia's capital Sunday, and plans for a peace and reconciliation conference were delayed for a second time.

Mogadishu has seen sporadic violence in recent days, ending more than a week's lull in fighting between insurgents and Ethiopian-backed government troops. Four days of bloodshed that started in late March killed hundreds of people -- and possibly more than 1,000 -- in the worst fighting in 15 years.

On Sunday, the chairman of a committee planning a peace and reconciliation conference said the meeting would be held June 14. The conference was supposed to be held this month, but had been postponed to May because of the violence.

"We are trying to reconcile the Somali clans, and we are waiting for international support," Ali Mahdi Mohmamed said Sunday.

Also Sunday, insurgents battled Ethiopian and Somali troops using machine guns and mortars. The death toll was not immediately clear; one day earlier, two Somali soldiers were fatally shot in the back in an ambush.

The battles in March started when Ethiopian troops used tanks and attack helicopters in an offensive to crush insurgents. The insurgents are linked to the Council of Islamic Courts, which was driven from power in December by Somali and Ethiopian soldiers, accompanied by U.S. Special Forces. The United States has accused the courts of having ties to al Qaeda.

The militants reject any secular government, and have sworn to fight until Somalia becomes an Islamic emirate.

The U.N. refugee agency says more than 200,000 people have fled Mogadishu since the beginning of February. The agency had earlier said 124,000 people fled -- highlighting the difficulty of getting accurate figures from a country with no effective central government or institutions.

Somalia has been mired in chaos since 1991, when warlords overthrew dictator Mohamed Siad Barre and then turned against each other. A national government was established in 2004 but has failed to assert any real control.