A car bomb exploded near a crowded market in a mainly Shiite area in Baghdad on Thursday, killing as many as 20 people, Iraqi officials said, in the fifth major attack in Iraq this month. The blast came a day after the US military said overall attacks nationwide have fallen to levels of the early months of the war, which began with the US-led invasion in March 2003. The car was parked near a bus terminal surrounded by shops in the eastern Shaab district when it blew up shortly after noon on Thursday, the officials said. Iraqi police and hospital officials, speaking on condition of anonymity because they weren't authorized to release the information, said the 20 killed included four children and four women. The officials said 35 people also were wounded. The US military confirmed the attack but said preliminary reports indicated eight people were killed and 14 were wounded.