Unshaken by the latest surge in violence, Iraqis braved the threat of bombs and attacks to vote Wednesday in key elections for a new parliament amid a massive security operation as the country slides deeper into sectarian strife.

Hundreds of thousands of troops and police fanned out to guard voting centers in the first nationwide balloting since the 2011 American pullout. Scattered attacks still took place north of Baghdad, killing at least three people and wounding 16.

Prime Minister Nouri al-Maliki, who has held power for eight years, faces growing criticism over government corruption and persistent bloodshed as sectarian tensions threaten to push Iraq back toward the brink of civil war.

The 63-year-old Shiite leader's State of Law party was widely expected to win the most seats in the 328-member parliament but to fall short of a majority. That would allow al-Maliki to keep his post only if he can cobble together a coalition — a task made more difficult given the divisions with former Sunni Arab and Kurdish allies.

Even some of al-Maliki's Shiite backers denounce him as a would-be dictator, amassing power for himself, but most in the majority sect see no alternative. Al-Maliki also has the support of neighboring powerhouse Iran, which aides have said will use its weight to push discontented Shiite factions into backing him for another term.

Polls opened across the energy-rich nation at 7 a.m. (0400 GMT, midnight Tuesday EST) and were to close at 6 p.m. There were 22 million eligible voters, choosing from among some 9,000 candidates.

In central Baghdad, police and army manned checkpoints roughly 500 meters (yards) apart, while pickup trucks with machine-guns perched on top roamed the streets. Much of the city looked deserted without the normal traffic congestion. Most stores were closed.

Voters are being subjected to multiple searches before being allowed inside polling centers and surrounding streets were blocked by police trucks and barbed wire.

"I decided to go and vote early while it's safe. Crowds attract attacks," Azhar Mohammed said as she and her husband approached a polling station in Baghdad's mainly Shiite Karradah district. The 37-year-old woman said her brother — a soldier — was killed last week in the northern city of Mosul.

"There has been a big failure in the way the country has been run and I think it is time to elect new people," she said, shrouded in black.

Not far away, 72-year-old Essam Shukr broke into tears as he remembered a son killed in a suicide bombing in Karradah last month. "I hope this election takes us to the shores of safety," he said. "We want a better life for our sons and grandchildren who cannot even go to playgrounds or amusement parks because of the bad security situation. We want a better life for all Iraqis."