Millions of ballot papers were still being counted after after the poll, the first election of a full-term government since Saddam Hussein was ousted in 2003.
The UN Security Council on Friday joined UN chief Kofi Annan in praising the legislative election and called for the rapid formation of a permanent government in Baghdad.
In stark contrast to a January poll, the election was marked by minimal violence and high voter-turnout, including in Sunni Arab areas that have previously boycotted the US-led political transition to sovereignty.
“For Iraq it is very important, as it will determine whether the country will slide further into civil war or perhaps can still be pulled back from the abyss,” said Joost Hiltermann from the International Crisis Group.
Amid a massive security operation, the number of voters appeared to have surpassed turnout in the October referendum and the January 30 elections.
An electoral official said the number of ballots was expected to be between 10 and 11 million, which could put turnout at just over 70 percent.
International monitors said the election had “generally” met international standards despite some procedural issues and praised the organisers for meeting a “difficult challenge.”
Head of the electoral commission, Ezzeddin Mohammadi, said the organisation had received 178 complaints, which would be examined by electoral officials and independent lawyers.
Abroad, 320,000 expatriate Iraqis voted in the election.
Although final results are not expected for at least two weeks, a Western diplomat said a preliminary estimate could be available in four to five days.
In rough estimates, Shi’ite parties seemed to have scored well in strongholds in the south, the main Kurdish Alliance was likely strong in the north, while turnout was high in Sunni regions.
In the western al-Anbar region, a bastion of support for the Sunni Arab nationalist insurgency, officials estimated turnout at 85-95 percent in the flashpoint town of Fallujah.
Some polling stations even ran out of ballot papers, so strong was the turnout. The electoral commission also forecast turnout at 75-80 percent in the hotspot of Ramadi.
Despite the huge challenge ahead of creating a viable government strong enough to crush violence, global leaders hailed the vote.
US President George W. Bush said it was a “major step forward” in having “a democratic Iraq, a country able to sustain itself and defend itself”.
Newspapers across the Arab world hailed Sunni Arab participation as a “turning point” that should grant legitimacy to a new government.
The Security Council on Friday hailed the landmark election and welcomed the high Sunni turnout.
Council members “are particularly encouraged that political parties representing all of Iraq’s communities participated in the election and by reports suggesting high voter turnout across Iraq,” said a statement read by Britain’s UN envoy Emyr Jones Parry.
It added that the 15-member council looked forward to “the rapid formation of a representative government” and stressed “the importance of inclusiveness, dialogue and national unity as Iraq’s political development moves forward.”
Earlier, UN chief Kofi Annan said “the participation by all communities in this historic election is another milestone in Iraq’s progress toward a democratic future and lays the foundation for national reconciliation.”
“Whatever the results of the election, there is a now an opportunity for a political process that offers all Iraqis the chance to play a part in building a peaceful, democratic, unified and prosperous Iraq,” the UN chief noted.
The Security Council also called for increased international assistance to Iraq.
But in an embarrassing revelation for efforts to quash the insurgency, a junior Iraqi minister admitted that police had captured Abu Musab al-Zarqawi, the presumed al-Qaeda leader in Iraq, but released him.
“He was arrested more than one year ago in Fallujah by Iraqi police,” deputy interior minister Hussain Kamal told news agency AFP. “It seems they did not recognise him, that’s why they released him.”
Zarqawi, who has a US$25-million bounty on his head, is the alleged mastermind of numerous bombings, hostage murders and armed attacks in Iraq.
The Pentagon said it could not confirm the capture.