A series of blasts struck the US-protected Green Zone on Thursday, but the US military said nobody was killed in the attack, which occurred on the American celebration of Thanksgiving. About 10 blasts were heard in central Baghdad just before 5 p.m., and a huge plume of black smoke rose into the sky as the sun was setting. The US government public address system in the Green Zone also warned people to "duck and cover" and to stay away from windows. Maj. Brad Leighton confirmed the area was hit by indirect fire, a term the US military uses for rocket or mortar attacks, but said nobody was killed. Some people were wounded, but they were not coalition forces, he said, declining to specify numbers or nationalities of those injured. An Iraqi police officer, who spoke on condition of anonymity because he wasn't authorized to release the information, said the blasts were caused by mortars, but that could not be independently confirmed.