The shootings and bombings, which also wounded dozens more, came with campaigning in full swing for the April 30 election and with violence at its highest level since 2008.
The unrest has been principally driven by anger in the Sunni Arab community over alleged mistreatment at the hands of the Shiite-led government and security forces, as well as a spillover from the civil war in neighbouring Syria.
Apart from the capital, today's attack struck in and around the mostly-Sunni cities of Mosul and Samarra to its north, and Ramadi and Fallujah to its west.
Militants also destroyed a bridge just north of the capital by setting off several bombs along it.
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More than 2,300 people have been killed in Iraq so far this year, according to an AFP tally.
Diplomats have urged the government to reach out to the disaffected Sunni minority to undercut support for militancy.
But with the election looming, Prime Minister Nuri al-Maliki and other Shiite leaders have been loath to be seen to make concessions.
Near-daily bloodshed is part of a long list of voter concerns that also include lengthy power cuts, poor wastewater treatment, rampant corruption and high unemployment.