Islamic insurgents and pro-government forces are firing mortar rounds at each other near the presidential palace in Somalia's capital in the fourth day of violence this week. A local independent human rights group says 11 civilians have been killed in Thursday's violence. 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 says his forces are 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.