Two bombs apparently targeting Iraqi security forces struck different areas in Baghdad on Tuesday, killing at least one civilian and wounding seven others, Iraqi officials said.

The first explosion occurred just before 9 a.m. in northern Baghdad as a police patrol passed through the Sulaikh area, but it missed its target and hit a civilian car instead, wounding four people, police said.

The U.S. military said the blast was caused by a pipe bomb and three children were wounded, two seriously. The attack was reported by the U.S.-allied Sunni group in the area, it said.

Another roadside bomb struck at 11:30 a.m. near an Iraqi army patrol on Nidhal Street in central Baghdad, killing one civilian and wounding three others, according to police and hospital officials, speaking on condition of anonymity because they weren't authorized to release the information.

Maj. Mark Cheadle, a spokesman for U.S. forces in Baghdad, said it appeared that Shiite extremists were to blame for the roadside bombing.

Violence has dropped dramatically in Iraq, especially in Baghdad, but the U.S. military has warned that Sunni and Shiite extremists maintain the ability to carry out deadly attacks.