A roadside bomb went off near a U. S. military convoy on Tuesday, damaging a Humvee, police source and witnesses told Xinhua.
"A roadside bomb detonated at about 8:00 a.m. (0500 GMT) near a passing U.S. convoy on the Jadriyah bridge in southern Baghdad, damaging a U.S. Humvee, killing and wounding the soldiers aboard," a police source told Xinhua on condition of anonymity.
A witness at the scene, Ghassan Ali, said he saw a U.S. Humvee caught fire while the U.S. troops blocked the roads and cordoned off the area.
"Two U.S. helicopters landed at the scene to evacuate the casualty," he added.
In a separate incident, the police source said that at least four people were wounded when another bomb detonated in the morning inside a mini-van carrying passengers near the Mission commercial compound in southern Baghdad.
Meanwhile, a mortar round landed on a house in the Zaafaraniyah neighborhood in southeastern part of the capital, wounding a civilian, the police said.
In downtown Baghdad, an Interior Ministry source said five people were killed and 17 others wounded when a car bomb parking at busy area in Shikh Omer district near a police station and a school, detonated at about 10:30 a.m. (0730 GMT).
The attack damaged several nearby old buildings and civilian cars, the source said.
The attacks marked the 4th anniversary of U.S.-led war on Iraq that toppled former Iraqi leader Saddam Hussein.
Earlier in the day, Saddam's deputy Taha Yassin Ramadan was executed in Baghdad. The Iraqi High Tribunal's appeals court confirmed Ramadan's death sentence on Monday.
Violence rages on in Iraq as car bombings, roadside bombs and assassination cause dozens of civilian casualties daily despite the presence of tens of thousands of U.S. and Iraqi soldiers across the capital in a major security crackdown aimed at curbing insurgency and sectarian violence in the war-torn country.