An Iraqi man casts his vote today at a polling center in Baghdad.

BAGHDAD - Iraq voted Wednesday in its first nationwide election since U.S. troops withdrew in 2011, with Prime Minister Nouri al-Maliki confident of victory and even offering an olive branch to his critics by inviting them to join him in a governing coalition.

But his optimism will do little to conceal the turmoil and violence that still stalk Iraq in the eight years he has held office, with the looming threat of the country sliding deeper into sectarian bloodshed and risking a breakup.

"Our victory is certain, but we are talking about how big is that certain success," he said after voting in Baghdad.

"Here we are today, successfully holding the ... election while no foreign troops exist on Iraqi soil. I call upon all the other groups to leave the past behind and start a new phase of good brotherly relations," said al-Maliki, who faces growing criticism over government corruption and persistent bloodshed as sectarian tensions threaten to push Iraq back toward the brink of civil war.

The election was held amid a massive security operation, with hundreds of thousands of troops and police deployed across the country to protect polling centers and voters. The streets of Baghdad, a city of 7 million, looked deserted. Police and soldiers manned checkpoints roughly 500 meters (yards) apart and pickup trucks mounted with machine guns roamed the streets that were otherwise devoid of the usual traffic jams.

Scattered attacks took place north and west of Baghdad, killing at least five people and wounding 16. Roadside bombs killed two women and two election workers in the northern town of Dibis.

Al-Maliki's upbeat comments sharply contrasted with voters' sentiments, which ranged from despair to a gritty resolve to participate despite the threat of violence.

"I see this election as the last chance, my last bet on Iraq. If things continue to be the same, I will leave, and this time for good," said Saad Sadiq Mustafa, a 55-year-old retired army officer who fled with his family to neighboring Syria to escape the worst Sunni-Shiite violence of 2006 and 2007 and came home in 2008. A Sunni Arab and a father of four from Baghdad, Mustafa voted for Ayad Allawi, a secular Shiite who became Iraq's first post-Saddam Hussein prime minister in 2004.

"We are living in a diverse country in which only seculars can maintain a balance between all ethnic and religious groups," he said.

Al-Maliki's State of Law bloc was widely expected to win the most seats in the 328-member parliament but fall short of a majority, according to analysts. That would allow al-Maliki to keep his post only if he can cobble together a coalition -- a task that took nine months after the last election in 2010.

Even some of his onetime Shiite backers accuse him of trying to amass power for himself, but many in the majority sect see no alternative to the 63-year-old al-Maliki or are looking for a successor who would follow in his footsteps and jealously guard Shiite political domination.

However, al-Maliki enjoys the crucial support of neighboring powerhouse Iran, which aides have said will use the vast influence it enjoys in Iraq to push discontented Shiite factions into backing him for another term.

Salam Ibrahim, a 25-year-old engineer and father of one, is a Shiite who places the sect's interests above all else.

"I believe the main mission of the leader I am looking for is to continue fighting for the survival of the Shiite community and force those who oppose it to acknowledge its right to govern as the majority," he said as he headed to vote in central Baghdad.

Al-Maliki said he would have no objection to an alliance with any other bloc, provided it denounced sectarianism and worked for Iraq's unity. But the Kurds had already suggested they will not be part of a coalition he leads, while some of his onetime Shiite allies may want to join with the Sunnis and Kurds to push al-Maliki out of contention.

"We have decided that joining an alliance with the prime minister is a red line for us," parliament's Sunni speaker Osama al-Nujaifi said as he voted. Last year, he called on al-Maliki to step down, accusing him of consolidating power in his hands.

Another thorny issue likely to dominate the post-election political scene is who gets to be the next president. The incumbent, ailing elderly statesman Jalal Talabani, a Kurd, has served the maximum two terms. His departure will revive calls by Iraqi Arabs, Shiite and Sunnis alike, for an Arab president. That, in turn, will strain relations between Baghdad and the self-ruled Kurdish region in the north, which are already tense over Baghdad's perceived meddling in Kurdish affairs.

In a statement, the U.N. Security Council welcomed the election and urged "Iraq's leaders to engage, as quickly as possible, to form a Government that represents the will and sovereignty of the Iraqi people."

For the election, stores were closed and many had long walks to the polls after authorities banned civilian vehicles to prevent car bombs. Voters were searched multiple times before being allowed inside polling centers, and surrounding streets were blocked by police trucks and barbed wire.

Hamid al-Hemiri and his wife, Haifaa Ahmed, walked five kilometers (three miles) to vote in Baghdad's Mansour district.

"We were determined to take part in the election to save our country and so that future generations don't curse us," he said. His wife added: "I am voting to stop the bloodshed in my country. Enough sorrow and pain."

Turnout of Iraq's 22 million eligible voters was estimated at about 60 percent, according to Muqdad al-Shuraifi, a senior election commission member. The figure, he explained, excluded "restive areas."

They chose from more than 9,000 candidates.

Authorities did not offer a timetable for releasing results, but they were expected to start trickling in to election officials in the coming days. In 2010, results weren't announced for about two weeks.

"I decided to go and vote early while it's safe. Crowds attract attacks," said Azhar Mohammed, a mother of four who voted with her husband shortly after 7 a.m. in Baghdad's mainly Shiite Karradah district. The 37-year-old woman said her brother -- a soldier -- was killed last week in the northern city of Mosul.

"There has been a big failure in the way the country has been run and I think it is time to elect new people," she said, shrouded in black.

Not far away, 72-year-old Essam Shukr wept as he remembered a son killed in a suicide bombing in Karradah last month. "I hope this election takes us to the shores of safety," he said. "We want a better life for our sons and grandchildren who cannot even go to playgrounds or amusement parks because of the bad security situation."

In Baghdad's mostly Shiite Sadr City district, for years a frequent target of bombings blamed on Sunni insurgents, elite counterterrorism forces were deployed and helicopters hovered. Double-decker buses took voters to the polls.

"We want to see real change in this country and real security. We are not happy with the performance of the current government and parliament," said 18-year-old Zulfikar Majid, a first-time voter in Baghdad's mainly Shiite Habibiya neighborhood.

Another first-time voter, Umm Jaafar of the southern city of Basra, said she had boycotted past elections because of the U.S. troops in Iraq.

"We hope that today's election would lead to change the current government, which has let us down despite all the money it has," she said as she and two of her children, also first-time voters, came out of a polling center in the mainly Shiite city.

Al-Maliki rose from relative obscurity to office in 2006, when sectarian violence began to spiral out of control, with Sunni militants and Shiite militias butchering each other. The bloodshed ebbed by 2008 after U.S.-backed Sunni tribesmen rose up to fight al-Qaida-linked militants and Shiite militias declared a cease-fire.

But attacks have surged in the past year, fueled in part by al-Maliki's moves last year to crush protests by Sunnis complaining of discrimination. Militants took over the city of Fallujah in Sunni-dominated Anbar province and parts of the provincial capital of Ramadi.

Army and police forces battling them for months have been unable to take most areas back, and voting was not held in parts of the vast province bordering Jordan and Syria.

The insurgents also have been emboldened by the civil war in Syria, where rebels are fighting to oust the regime of President Bashar Assad, a follower of a Shiite offshoot sect. The rebels are dominated by Islamists and members of al-Qaida-linked or inspired groups, including the Islamic State of Iraq and the Levant. Shiite militiamen from Iraq fight on the side of Assad's forces.

Last year, the death toll in Iraq climbed to its highest levels since the worst of the sectarian strife in 2006 and 2007. The U.N. says 8,868 people were killed in 2013, and about 2,000 people were killed in the first three months of this year.

Retired army officer Abu Abdullah, a native of Amiriyat Fallujah in Anbar who would not give his full name, boycotted the vote over what he said was the failure of Sunni Arab politicians to protect their community.

"I am not ready to take a risk or even be killed for the sake of corrupt people who might be in the next parliament or government because I am sure they will make a deal with al-Maliki and forget about us."