FALLUJAH, Iraq (AP) -- A suicide bomber blew himself up inside a ballot-counting center in western Iraq late Thursday, officials said, killing at least four people after the polls closed in elections in two of the country's most volatile provinces that had already been delayed once over security fears.
The attacker struck at the end of what had been a relatively calm election day in Sunni-majority Anbar and Ninevah provinces, both hotbeds of anti-government unrest. A decision by the central government to postpone elections there had raised concerns that voters there would be disenfranchised, adding to their grievances with the Shiite-led government.
Security had been a top concern ahead of Thursday's vote. Thousands of policemen and soldiers were deployed to secure the elections, and authorities imposed a vehicle ban in major cities in the two provinces to protect against car bombings as voting got underway for candidates who will serve on provincial-level councils.
Iraq is weathering its worst spike in violence in half a decade, with nearly 2,000 people killed since the start of April. Much of the violence is the work of the Sunni extremist al-Qaida branch in Iraq.
The bombing happened in Ramadi, the provincial capital of Anbar, 115 kilometers (70 miles) west of Baghdad. There were conflicting casualty tolls. Two police officers in Anbar said at least four people were killed and five more were wounded. Talib Humadi, a councilman from Anbar, said the blast killed seven people.
Authorities quickly imposed a curfew throughout the province after the attack.
Earlier, police said a mortar attack killed one person in Ramadi while polls were open. The police officials spoke on condition of anonymity because they weren't authorized to speak to reporters.
Iraq has successfully held elections in adverse conditions in the past by surging security forces onto the streets for short periods of time. But Anbar and Ninevah posed a special challenge, as the two provinces have seen some of the largest rallies in a months-long wave of Sunni anti-government protests as well as attacks by militants and multiple assassinations of candidates.
In Fallujah, 65 kilometers (40 miles) west of the Iraqi capital, checkpoints sealed off the city and prevented cars from getting in. Streets in the morning were empty except for ambulances, police and army vehicles, and a small number of cars permitted by electoral authorities.
Voters trickling into polling centers were searched twice before being allowed in. Police offered some voters rides to the polls in pickup tricks, as did political parties using minibuses emblazoned with pictures of candidates.
Fallujah voter Fuad Enad Mohammed, 26, said he wanted to see change for his Sunni sect in Anbar.
"With these elections, we will try to bring officials better than the ones in the previous council who didn't offer anything and were not real defenders of Sunnis," he said.
Local authorities eventually lifted the vehicle bans in the afternoon, apparently to encourage people to head to the voting centers by car instead of walking under the scorching sun.
The U.S. Embassy in Baghdad hailed the vote as "an important step toward solidifying Iraq's democratic future."
Iraqis voted in 12 of Iraq's 18 provinces two months ago. Authorities cited security concerns in delaying the Anbar and Ninevah vote, though some Iraqis questioned that rationale and dismissed it as a political ploy.
Some 2.8 million Iraqis were eligible to vote in more than 1,200 polling centers the two provinces. Nearly 100,000 members of the security forces had a chance to vote in special elections on Monday so they could be on hand to secure the balloting.
Hundreds of candidates from 28 political blocs in Ninevah and 16 in Anbar are hoping to secure seats. There are 39 seats up for grabs in Ninevah and 30 in Anbar.
Among the groups hoping for a strong showing are Sunni parliament speaker Osama al-Nujaifi's United bloc, Deputy Prime Minister Saleh Al-Mutlaq's Arab Iraqiya coalition and the secular but Sunni-dominated Iraqiya bloc headed by Shiite politician Ayad Allawi.
The provincial councils have some say over regional security matters and have the ability to negotiate local business deals and allocate government funds. But provincial council members frequently complain that they are hamstrung by restrictions from federal authorities over how to spend the money.
The councils also choose provincial governors and have the right under Iraq's constitution to call for a referendum to organize into a federal region -- a move that could give them considerable autonomy from the central government in Baghdad.