Officials in the northern Iraqi city of Mosul say three American civilians have been killed and two wounded in a drive-by shooting.
Local police say the victims were traveling in a car Monday when gunmen opened fire. Further details were not released.
A report that the five Americans were working for a private volunteer organization could not be confirmed.
There have been several recent attacks by insurgents in Iraq against civilians seen to be working with the U.S.-led coalition.
Earlier, police in the northern Iraqi city of Kirkuk said an Arab member of the city council, Akar Nizal, was shot and killed in his car near the local government building. Police are searching for the killers.
News reports described the victim as an outspoken member of the council in oil-rich Kirkuk, a city that has a Kurdish majority in a region where a number of ethnic minorities are struggling for representation.
On Sunday, U.S. military officials said four American soldiers had been killed in two recent roadside bombings in Baghdad.