Iraqi police and witnesses say a blast apparently targeting American troops has struck a local council building in Baghdad's Shi'ite Sadr City district. A police officer says at least two Iraqi civilians have been killed and seven wounded in Tuesday's explosion. The US military confirms a blast near the district advisory council building in Sadr City but isn't releasing more details pending reports from the scene. The local policeman says the blast occurred shortly after 9 a.m. near the deputy council chief's office as Americans approached. The policeman spoke on condition of anonymity because he wasn't authorized to release the information.