Gunmen killed three Iraqi candidates in separate incidents on Thursday, two days before Iraq holds provincial polls that will test the war-weary country's fragile democracy.
The run-up to Saturday's provincial vote -- seen as a key test of Iraq's progress since the 2003 U.S.-led invasion -- had been relatively violence-free but the killings are certain to raise fears that militants could throw polling day into chaos.
Hazem Salem Ahmed, a Sunni Arab candidate from the National Unity List, was shot outside his home in the volatile northern city of Mosul, where minority Kurds and Sunnis are facing off and where al-Qaeda and other insurgents have made a last stand.
In Baghdad's Amiriya district, gunmen killed candidate Omar Faruq al-Ani, a member of the Iraqi Islamic Party, near his home after a campaign rally.
Candidate Abbas Farhan from the National Movement of Reform and Development was gunned down in a village near the town of Mandili in Diyala Province, northeast of Baghdad, near the Iranian border, also after a campaign rally.
The rash of shootings brought to at least five the number of candidates slain before the polls. The election will select local leaders in 14 out of 18 provinces and could alter Iraq's delicate balance of power.
Tens of thousands of police and soldiers will guard Saturday's ballot, when about 15 million Iraqis are expected to vote in 14 out of 18 provinces.
Sunni Arabs, a minority disempowered after the U.S.-led invasion toppled Saddam Hussein in 2003, are likely to gain power in some areas after boycotting elections in 2005.
But they are also competing amongst themselves in western Iraq as upstart groups, many associated with a neighborhood guard movement that stood up to Islamist al-Qaeda, challenge more established parties.
Shiite parties, including those backed by Prime Minister Nouri al-Maliki, are competing across the largely Shiite south and other areas.
The lead-up to the polls has generally been less violent than some U.S. and Iraqi officials had feared.
U.S. military spokesman Brigadier-General David Perkins said there were just nine attacks on Wednesday, when soldiers, displaced people and prisoners voted in early polls, compared to 92 attacks daily in January 2005 when Iraqis last voted.
"There are obviously people, al-Qaeda, other terrorists, special groups, criminals, who see the progress of democracy as a threat to them. They want an Iraq that is ruled by fear," Perkins told Reuters Television.
Security will be tight for the polls, with a curfew and a vehicle ban intended to discourage car bomb attacks.
Iraqi security forces are taking the lead and U.S. forces, preparing to withdraw by the end of 2011, are standing by to provide air support if needed.
As violence drops sharply across Iraq, candidates have embraced a colorful and vocal campaign, plastering posters across the country, holding festive rallies in parks and floating balloons carrying their names.
There have been hiccups. Four candidates from a list backed by followers of anti-American Shiite cleric Moqtada al-Sadr were arrested on Thursday.
Sadr's followers have been on the back foot heading into Saturday's vote after a government crackdown on their Mehdi Army militia last year.
But they are hoping to claim a greater share of local power in the capital after largely skipping the last provincial elections in Jan. 2005.