Baghdad , Iraq -LRB- CNN -RRB- -- Three people were killed when a parked car rigged with explosives blew up Saturday in Najaf on the eve of parliamentary elections , the Interior Ministry said . At least 54 others -- 17 Iraqis and 37 Iranians -- were injured in the attack near the Imam Ali Holy Shrine , which houses the tomb of Ali , cousin of the Prophet Mohammed . Two of the dead were Iranians , the interior official said . Najaf , about 100 miles -LRB- 160 kilometers -RRB- south of Baghdad , is frequented by Shiite pilgrims from Iran . Iraqis will go to the polls Sunday to choose a 325-member parliament . The election has been marred by violence despite heavy security . It is Iraq 's fifth nationwide vote since 2003 , but only the second for a full four-year-term parliament . Three attacks happened Thursday during early voting for those who will be unable to cast ballots Sunday , such as military and security personnel , detainees , hospital staff , and patients . A total of 12 people were killed and dozens were wounded . There have been warnings of further insurgent attacks around the vote . These are Iraq 's first national elections since 2005 , when the Sunni Arab population boycotted the elections and the political process . A Shiite-led government emerged and the Sunnis , feeling disenfranchised , went on to form the main part of the insurgency . The United Nations Assistance Mission for Iraq calls the elections an `` important milestone in Iraq 's democratic progress , '' serving to strengthen the country 's sovereignty and independence as the United States draws down its military presence there . Sunday 's elections were supposed to happen in January but were delayed because of political disagreements and a delay in passing the election law that paved the way for this vote . There are 18.9 million eligible voters , casting ballots for 325 seats in the Council of Representatives , as Iraq 's parliament is called . The seats represent Iraq 's 18 provinces . At least a quarter of the positions -- 82 -- are guaranteed to go to women , and eight more have been allocated for minorities . They include five set aside for Christians and one each for the Shabak , Sabaeans -LRB- Mandaeans -RRB- , and Yazidis . The number of seats is increasing from the previous 275 . Seat allocation was based on 2005 population data from the Ministry of Trade and adjusted for a 2.8 percent annual growth across all governates . Voting for Iraqis abroad also is happening in 16 countries starting Friday -- including the United States , United Kingdom , Turkey , Iran , Canada and others in the Middle East and Europe . There are no exact figures for those eligible to cast ballots abroad . Estimates on turnout have ranged anywhere from 300,000 to 3 million . Around 6,200 candidates from more than 80 political entities are vying for seats . It is the first parliamentary vote to use an open list , in which the voters vote for political entities and , if they want , also can vote for candidates within those entities , according to the U.N. Assistance Mission . Although open lists complicates the training of election staff and the counting of votes , the system enhances the role of the voter in the election beyond casting a vote simply for a political party , the assistance mission says . At least 25 percent of the candidates on the ballot list of each political entity must be women . The assistance mission is providing technical assistance to the Independent High Electoral Commission , which is organizing the vote . The commission has ordered that all political campaigning must end as of 7 a.m. Saturday . A number of other special measures are being put in place for security reasons . Since Monday , there has been a ban on motorcycles and bicycles in Baghdad until further notice , and on Sunday a two-day ban on any vehicles in cities will begin , Iraqi authorities announced on state television . Provincial borders will be sealed , preventing movements between provinces , from Saturday to Monday . And international borders and all airports will be shut from midnight Saturday . A curfew will be in place in cities from midnight to 5 a.m. on Saturday , Sunday and Monday , officials said . Civilians may not carry weapons on those days , they said . More than 47,000 polling stations will be open across the country , each one able to accept a maximum number of 420 voters . Polling stations are clustered into polling centers . Polls will be open from 7 a.m. to 5 p.m. All those in line at the time the polls are open will be able to vote . About 300,000 trained election staff -- mostly teachers , principals , and lawyers -- will be on hand at polling sites . There will be more than 494,000 local and international observers , according to the Independent High Electoral Commission . The number includes about 500 to 600 international observers , according to the United Nations . Voter turnout figures should be available shortly after polls close , and preliminary results are expected by Tuesday or Wednesday , the United Nations said . Results will start emerging for each province as soon as 30 percent of polling centers in that province are tallied . Counting will take place at the polling stations at the end of voting , under the gaze of observers . Ballots will be counted twice to ensure accuracy . 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 . CNN 's Jomana Karadsheh contributed to this report .