Baghdad, Iraq (CNN) -- Violent attacks on election day didn't stop large numbers of Iraqis from successfully casting their votes in key parliamentary elections Sunday.



"Yes, we were scared after we heard these bombings, but we just had to come," said a woman who identified herself only as Ghisoun. Her two children were at her side.



"It's an opportunity we can't miss -- not for us, but for our children," she said.



Polls in Iraq to elect a 325-member parliament closed Sunday evening, capping an electoral process in which militants intent on disrupting the vote carried out dozens of attacks that killed 38 people.



Despite the risks, voter turnout could reach 55 percent, a senior U.S. official told CNN.



Another voter, Ali Abdul Hassan, also risked the uncertainty of voting Sunday with his 2-month-old infant.



"I want my baby to start voting early," he said.



The general feeling expressed by voters on election day was a longing for change and for a government that will be able to provide basic things such as water, electricity, jobs and security.



A woman in line to vote in Baghdad said her vote was a way of fighting back against acts of terrorism in Iraq.



Preliminary results are expected by Wednesday, the United Nations said. Results will start emerging for each province as soon as votes are tallied from 30 percent of polling centers in that province.



About 60 security incidents were reported throughout the country Sunday, the senior U.S. official said. These included fatal mortar and rocket attacks in various Baghdad neighborhoods.



Secretary of Defense Robert Gates said those reports of mortar attacks in Baghdad had not yet been confirmed.



According to Gates, Gen. Ray Odierno, the top U.S. commander in Iraq, "had expected a significant number of high-profile attacks, both suicide vests and truck and car bombs, but the security situation, the efforts of the Iraqi Security Forces are such that al Qaeda in Iraq was forced to change their tactics."



Speaking at the White House, President Obama also downplayed Sunday's violence.



Some violence was expected, Obama said, but "overall, the level of security, and the prevention of destabilizing attacks, speaks to the growing capability and professionalism of Iraqi security forces, which took the lead in providing protection at the polls."



The success of the vote showed that "the future of Iraq belongs to the people of Iraq," Obama said.



The United States does not support particular candidates in Iraq, but does support Iraqis' right to elect their representatives, he said.



"We know there will be very difficult days ahead in Iraq," Obama said. "There will probably be more violence. But, like any sovereign, independent nation, Iraq must be free to chart its own course."



Secretary of State Hillary Clinton praised Iraq's High Electoral Commission and security forces for running and securing the vote.



"I congratulate all the people of Iraq who participated in national elections today and over the past three days," she said in a statement. "There is no better rebuke to the violent extremists who seek to derail Iraq's progress."



Counting was taking place at the polling stations at the end of voting, under the gaze of observers. Ballots will be counted twice to ensure accuracy, according to the U.N. Assistance Mission for Iraq.



The number of ballots cast will be reconciled with the number of ballots issued to each polling station, and in case of a significant discrepancy, the station will be audited, the U.N. said.



Authorities in Baghdad announced a curfew on the capital from 10 p.m. Sunday until 5 a.m. Monday.



In a statement Sunday, Obama said: "I have great respect for the millions of Iraqis who refused to be deterred by acts of violence, and who exercised their right to vote today."



Referring to the day's violence, he added: "We mourn the tragic loss of life today, and honor the courage and resilience of the Iraqi people who once again defied threats to advance their
Who carried out attacks as Iraqis head to polls? who congratulates iraqis When are the results expected according the U.N? who closed in iraq Polls closed in which country? what can't be missed?
militants Secretary of State Hillary Clinton by Wednesday, Polls Iraq an opportunity
question: Who carried out attacks as Iraqis head to polls?, answer: militants | question: who congratulates iraqis, answer: Secretary of State Hillary Clinton | question: When are the results expected according the U.N?, answer: by Wednesday, | question: who closed in iraq, answer: Polls | question: Polls closed in which country?, answer: Iraq | question: what can't be missed?, answer: an opportunity