Nearly 50 people were also wounded in the attacks which struck in and around Baghdad, and in Salaheddin and Kirkuk provinces to its north, medical and security officials said.
In the capital, a car bomb killed four people in a shopping area of the Sunni-majority northern neighbourhood of Saba Abkar, while a policeman was shot dead in another Sunni-dominated district in the south.
On Baghdad's northern outskirts, two policemen were killed by a roadside bomb.
They included a truck blown up by a suicide bomber, a corpse booby-trapped with explosives, and a roadside bomb near a school.
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Violence is running at its highest levels since 2006-7 when Iraq was gripped by a brutal Sunni-Shiite sectarian war left tens of thousands dead.
More than 900 people were killed in Iraq last month, according to figures separately compiled by the United Nations and the Baghdad government.
More than 4,000 have been killed so far this year, according to an AFP tally.
But the violence continues unabated, with analysts and diplomats saying the Shiite-led government needs to do more to reach out to the disaffected Sunni Arab minority to reduce support for militancy.