The latest killing brings the number of American soldiers killed in the past 24 hours to five.
US military officials said soldiers came under attack with small arms, rocket-propelled grenades (RPGs) and possibly an improvised explosive device near Abu Ghuraib.
The attack came hours after three American soldiers were killed in Baquoba near Baghdad in a grenade attack.
According to a spokesman of the US occupation forces, the soldiers from the 4th Infantry Division were guarding a children's hospital in Baqouba, northeast of Baghdad when resistance fighters attacked them with grenades.
Four US soldiers were wounded in the attack.
The deaths of the soldiers brought to 163 the number of troops killed in Iraq since the start of the invasion, 16 more than were killed in the 1991 Gulf War.
The resistance attacks on the US forces have been averaging 12 a day, according to the military.
Meanwhile, eyewitnesses told our correspondent that US soldiers shot dead an Iraqi civilian and wounded six others in the central city of Karbala late on Saturday.
The incident occured when American troops were providing back up to Iraqi policemen, who were trying to capture so called "armed gangs" selling contraband goods in the area.
In Baghdad's al-Shoala neighbourhood, the commander of Iraq's National Police Academy was wounded during a raid against suspected thieves, police said.
Iraq’s Brigadier Ahmed Kadhim, 56, was shot around 1am (2200 GMT) while leading the raid, said his assistant Captain Mushtak Fadhil.
|Kidnappings, car thefts and carjackings are getting worse|
He said the police were trying to arrest five suspected thieves when shots were fired. Kadhim was shot in the right calf and taken to a hospital. Five other policemen were wounded, including one critically.
Fadhil said five suspected thieves were arrested.
Baghdadis have complained that kidnappings, car thefts and carjackings are getting worse in the city, which is patrolled by Iraqi police, many of whom carry sidearms. There are about 60 police stations in the city.
There were also reports that shots were fired along the main highway leading to the northern city of Mosul, where deposed President Saddam Hussein’s sons Uday and Qusay were killed on Tuesday, but details weren't immediately available.
US troops charged
Abusing POWs is a violation of
the Geneva conventions
In other developments, four US soldiers serving in Iraq have been charged with abusing Iraqi prisoners of war (POWs).
They are now awating a decision whether they will be court-martialed, said a US defence official on Saturday.
It is the first time US personnel have been formally accused of mistreating Iraqi POWs since the beginning of the US-led invasion and occupation.
Details of the incident leading to the charges were not released.
The charges came three days after human rights group Amnesty International issued a scathing report saying it had collected information accusing US troops of torture and ill-treatment.