Eleven civilians were killed Thursday when Islamic insurgents and pro-government forces fired mortar rounds at each other near the presidential palace in Somalia's capital in the fourth day of violence this week. An Associated Press reporter saw the insurgents firing mortars in the direction of the presidential palace and government forces firing back. It is unclear if the shells hit the palace. Insurgents have targeted it in the past without damaging it. A rebel commander said his forces were running out of ammunition. He spoke on condition of anonymity because he was discussing sensitive information. Insurgents have tried to topple the weak, Western-backed government since 2006.