Witnesses said at least one US soldier was hurt in an attack on a military convoy in the Zayouna district in central Baghdad on Saturday night.
They told Aljazeera's correspondent in Baghdad that the explosive device damaged an army vehicle. US forces immediately cordoned off the area and denied access to the scene.
In a separate attack, resistance fighters fired a rocket close to the US-led coalition headquarters in central Baghdad. There were no reported injuries.
A US army spokesperson confirmed that two explosions were heard in close succession echoing across the city.
US death toll
This is the third rocket attack on Baghdad in a week. In that time 30 soldiers have been killed in attacks across Iraq, the highest number since the invasion of the country in April.
The rocket landed close to the coalition headquarters, landing in the garden of a train station close to the sprawling building that houses US occupation force officials.
In a further attack, an explosion device was detonated at an oil pipeline in the Hatra area, south of the province of Mosul, in the north of the country.
Witnesses told Aljazeera's correspondent the explosion set the pipeline ablaze.
The pipeline links northern Iraqi refineries with the Turkish port of Jihan port. It is the latest in a string of attacks on Iraqi oil pipelines.
Three rockets were fired at the Coalition building on Tuesday, wounding four people. Further attacks were launched against the building later in the week.
Those blasts took place inside the US controlled ''green zone'', a huge complex formerly home to one of Saddam Hussein's palaces, which includes US military bases.
Minutes after the latest attack, planes were heard flying above the city. US armoured vehicles with searchlights patrolled the river bank on the east side of the Tigris.