A booby-trapped car struck a police patrol in the city of Mosul, some 400 km north of here, killing four policemen and two passers-by and wounding another policeman, reported Xinhua citing a police source.
In another incident in Mosul, a policeman shot dead two gunmen after they were caught planting a roadside bomb, the source said.
Also in Mosul, a roadside bomb went off near a police patrol, killing a child and wounding three policemen, the source added.
Three policemen were killed and a fourth was wounded in a roadside bomb in Duluiyah city, some 90 km north of here, police said.
In Iraq's eastern province of Diyala, a civilian was killed and six were wounded in a bomb explosion late Tuesday outside a mosque in al-Gatoon area, west of the provincial capital city of Baquba, some 65 km northeast of Baghdad, according to a police source.
On Wednesday morning, two civilians were killed in separate attacks by gunmen near Baquba, the source added.
Iraq is witnessing its worst eruption of violence in five years, raising fears that the latest bloodshed is bringing the country back to a full-blown civil conflict that peaked in 2006 and 2007, when monthly death toll sometimes exceeded 3,000.