An explosive device was lobbed at an American vehicle in the Zayyouna neighbourhood of Baghdad, eyewitnesses told Aljazeera.
US troops cordoned off the area and launched raids in the surrounding neighbourhood to find the assailants.
Five other US soldiers and an Iraqi translator were injured in two separate attacks in the capital, said American military officials.
Two American soldiers were injured when an explosive device was thrown at their convoy on the road leading to Baghdad's airport.
US soldiers come under almost daily attacks on this road, which leads to an American military base.
Three US soldiers and an Iraqi translator were wounded when anti-tank rockets and bombs were fired at occupation troops near the Baghdad police headquarters.
Earlier, a US patrol came under rocket-propelled grenade attack near the northeast city of Ba’aquba, eyewitnesses told our correspondent.
There were no casualties reported.
Iraqis protest the American
Iraqi police also opened fire at armed men who fired RPGs at a US patrol in Khaldiya, 100 km west of Baghdad, triggering havoc in the village.
A gunfight erupted between the police and the assailants, while occupation troops stormed homes to capture their attackers.
Local residents protested the presence of occupation troops and set the town hall and a police post on fire. Helicopter-backed inforcements were brought in before calm was restored.
Overnight on Sunday, a US soldier and two Iraqi civilians were also wounded near Ba’aquba, 60 km north of the capital, as occupation troops continued to scour the area for loyalists of ousted Iraqi President Saddam Hussein.
An explosive device was thrown at an American patrol, sparking a gunfight between the assailants and occupation troops. US forces detained 12 Iraqis suspected of participating in the attack.
Early on Monday US forces said they captured a key Hussein loyalist in Tikrit, the ousted leader’s hometown.
Occupation troops have conducted 300 patrols, 11 raids and arrested dozens of people in the last 24 hours as part of Task Force Iron Horse, the codename for the operation aimed at finding Hussein.