The bomber blew up his car on Monday, targeting an Iraqi police patrol near the Iranian embassy, which is near a main checkpoint into the fortified Green Zone, said Major-General Abdul-Razaq al-Samarie, the top Baghdad police officer.
Two civilians and a policeman were killed and six Iraqis were wounded, including five policemen, al-Samarie said.
At about 5am, seven carloads of armed men, some wearing police commando uniforms, raided homes and a mosque in northern Baghdad's predominantly Sunni Arab neighbourhood of Toubji, shooting dead three men and detaining more than 20.
Three were later freed, but the rest remained unaccounted for.
Another eight bullet-riddled bodies were found in a field near Dujail, about 80km north of Baghdad, police said.
They were among 35 men who failed to get accepted into a police academy in Baghdad, 23 of whom were found slain on Sunday.
The car bombing took place near
the Iranian embassy
From the loudspeakers of mosques in the nearby city of Samarra, calls were made by Sunni religious and political leaders to stage protests and a three-day strike starting on Tuesday to denounce the killings.
US soldiers killed
Two Kuwait-based US airmen were killed and a third was wounded in a roadside bomb attack on Sunday near Taji, where a US air base is located 20km north of Baghdad, the military said.
Another roadside bomb killed a US soldier on Monday during a foot patrol in southwestern Baghdad.
The deaths brought the number of US military personnel killed since the war in Iraq began in March 2003 to at least 2227, according to an Associated Press count.
- Two policemen were killed and three wounded when a car bomb exploded in the southern Dura district of the capital.
- Two civilians were wounded when a roadside bomb exploded near an Iraqi police patrol in central Baghdad.
- An Iraqi army soldier was killed and another wounded when their patrol was struck by a roadside bomb in eastern Mosul.
- Police said attackers killed a female employee working for a US army base in the town of Ad-Dawr.
- Two civilians were wounded when a car bomb exploded near a joint Iraqi-US patrol in southern Baghdad.
- An Iraqi civilian was killed and four were wounded when a car bomb exploded in Mahmudiya. The target of the explosion was not clear.