Iraq's borders and its main airport have been closed in a bid to halt the violence ahead of Sunday's election.
There is a ghostly quiet in many Iraqi cities as security is stepped up
The measures are part of an unprecedented security operation that correspondents say has brought normal life in Iraq to a standstill.
But attacks have continued. Eight people died in a suicide bombing in the town of Khanaqin, north-east of Baghdad and violence also flared elsewhere.
Over the past week, many polling stations have also been attacked.
In other developments:
- UK troops in the southern city of Basra say they have seized explosives and arrested several Iraqis suspected of plotting a bombing campaign
- The Iraqi government says it has arrested three close aides of the alleged leader of al-Qaeda in Iraq, Abu Musab al-Zarqawi, one described as his Baghdad commander
- Zarqawi supporters claim to have killed a candidate on interim Prime Minister Iyad Allawi's list and will show the video later on the internet
- Former US President Jimmy Carter urges the US government to end its "unwarranted intrusion" in Iraqi affairs as soon as possible but says he believes it will be reluctant to relinquish control, in an interview with the BBC.
A record number of US soldiers are reported to be on duty to enforce security measures, which also include a dusk-to-dawn curfew in most cities and a ban on travel between provinces.
Friday: Expatriate voting begins; overnight curfews in Iraq
Saturday: Borders and airport closed for three days
Sunday: Election day, cars banned from roads, polls open 0700 (0400 GMT) and close 1700 (1400 GMT)
28,000 voting booths in some 5,300 polling centres
Next week: Vote counting for 4 or 5 days
Early Feb: Final results announced
Early March: PM appointed
Late March: Government formed
Iraq's borders and the main international airport in Baghdad have been closed for three days around Sunday's poll, in which voters will elect a 275-member transitional National Assembly to draft a constitution.
Correspondents say many Iraqi cities feel like ghost towns, as residents sit out the feared crescendo of violence around the election.
Officials said three Iraqi soldiers and five civilians - reportedly including a child - were killed when a bomber blew himself up in Khanaqin, a mainly Kurdish town close to the Iranian border.
At least six people were reported injured.
An Iraqi soldier was killed by a mortar in the central town of Suwayrah, authorities said.
Associated Press news agency pictures showed five dead bodies, one decapitated, lying in a street in Ramadi. The agency said they were Iraqis militants accused of working with the Americans.
In Baghdad, bursts of heavy gunfire were reported close to the Green Zone, the heavily fortified compound that houses the US embassy and the interim Iraqi government.
Detonations shook the city during Saturday afternoon as Iraqi soldiers erected barricades in the streets and US fighter jets roared through the sky in what correspondents said was a show of force.
Despite the ongoing attacks, the BBC's Paul Wood in Baghdad says so far there has not been the spectacular bomb attack the US military says insurgents were planning.
Some Sunni political parties have urged Iraqis to boycott the election. In a poll conducted by Zogby International, 76% of Sunni Arabs said they "definitely would not vote". Only 9% said they would vote.
The minority Sunni community dominated Iraqi politics during the regime of Saddam Hussein.
But the election is expected to lead to a power shift in favour of majority Shia Muslims.
Sunday's vote will be supervised by 828 international monitors, with a number of foreign embassies also providing staff to act as monitors.
In 14 countries overseas - from Australia, the Middle East, Europe and North America - Iraqis are continuing to vote. However, turnout is expected to be significantly lower than the 280,000 people registered to vote.
You can watch John Simpson's Panorama programme on the state of Iraq on BBC One on Sunday 30 January at 2215 GMT and on BBC World on Saturday 5 February at 0810, 1210 and 2210 GMT.