Up to 10 million Iraqis turned out to vote in a referendum on Saturday, protected by a security screen that deterred all but a few ineffectual insurgent attacks.
The Sunni Arab minority turned out in force for the first time since US troops toppled Saddam Hussein, a Sunni, bolstering the "no" vote against a constitution drawn up by a parliament elected in January and led by Shiites and Kurds.
Fighting and fear kept voters away in some Sunni cities in the west and north. Six Iraqi soldiers were killed in two attacks. Although three mortar rounds fell near one Baghdad voting site, the only people hurt while voting included several hit by bullets from nervous police and troops.
Militants seized ballot boxes in one Baghdad voting station. More than 40 people were killed during January's vote in more than 100 insurgent attacks, including suicide bombings. As in January, joyful or defiant voters waved index fingers stained with the purple ink that proved they had voted.
Turnout among the 15.5 million voters may have been around 10 million, Electoral Commission member Farid Ayar said. At least eight of 18 provinces saw turnout above 66 per cent, but in two or three, it was below 33 per cent, officials said. Though counts got under way as soon as 10 hours of voting ended at 5pm local time, election officers said it may be a day or more before any official indication of the result.
Iraq's communal arithmetic and healthy turnouts in Shiite and Kurdish areas kept government officials fairly confident of a "yes" vote in spite of Sunni defiance and some strong "no" voting among nationalist Shiites in the south. There is a veto clause if two thirds of voters in three of 18 provinces reject the charter.
Elsewhere in heavily Sunni Anbar province, however, clashes between militants and US and Iraqi forces in the provincial capital Ramadi and fear of fighting in other towns kept people away. No overall turnout figure was immediately available.
The United States, with more than 150,000 troops, wants a constitution in place on a tight schedule and has bargained hard to narrow the gap between Sunni moderates and the Shiite and Kurdish-led government.
A US-brokered compromise last week secured a promise that the constitution, if approved, would be reviewed by a new parliament, involving Sunnis, to be elected in December. That means more hard bargaining ahead, particularly on key issues such as the role of Islam in the law and the powers of federal regions, especially over oil and water resources, Reuters reports.