Bomb and gun attacks across Iraq on Sunday killed six people, among them three policemen, and wounded another nine, security officials said.
In the deadliest attack, militants in military uniforms killed three people in a car at a fake checkpoint they set up west of the restive ethnically mixed city of Baquba, an Iraqi army colonel in the provincial security command centre said.
In another incident in Diyala province, of which Baquba is the capital, two policemen were killed when gunmen opened fire at their checkpoint in Al-Saadiyah town.
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And in the main northern city of Mosul, a magnetic "sticky bomb" attached to a police car in the centre of the city killed a policeman and wounded four others, local police said.
Meanwhile in Baghdad, three people were wounded by two separate roadside bomb attacks in Zafraniyah and Shuala districts, an interior ministry official said.
Two policemen were also wounded when explosives attached to a motorcycle blew up near a petrol station in town of Tuz Khurmatu, 175 kilometres (110 miles) north of the capital.
Sunday's violence comes after Al-Qaeda's front group in Iraq threatened a campaign of 100 attacks, starting in mid-August, to avenge the death of Osama bin Laden in a US special forces raid in Pakistan in May.
Violence is down across Iraq from its peak in 2006 and 2007, but attacks remain common. A total of 259 people were killed in violence in Iraq in July, according to official figures, the second-highest figure in 2011.