There were conflicting reports about the circumstances: the Americans said they were returning fire from a nearby building and found the two dead men there afterward. However, the Nineveh provincial operations center said that the policemen were at a checkpoint when the Americans suddenly opened fire.

Over all, there seemed much eagerness to vote, but also confusion. Some voters showed up at the polling place closest to their home instead of the one they were assigned to because of the ban on driving. Others were turned away because their names were not on voter rolls.

Voter registration is organized around a national system for delivering food rations, a holdover from the Saddam Hussein era. Voters have to consult two lists to find out if they are registered at a given polling station. First, each person has to find the name of his or her food ration distributor. Then the voter must consult a much larger list of all of the families served by that distributor. If the voter’s name is missing, he or she cannot vote at that station.

Some frustrated Iraqis gave up, while others reported going from center to center before finding the one associated with their distributor.

Nasreen Yousif, a 54-year-old Christian, visited three polling places in the New Baghdad district of the capital but could not find her name at any of them. “Now I am going home,” she said. “Maybe there is a fourth school, but it is too far and I can’t walk any more.”

She added: “It is obviously a mess. If it is not a mess, where is my name?”

The Iraqi government and election officials blamed voters for the confusion.