The suicide bomber detonated a car bomb near a funeral procession. Half of those killed were policemen guarding the march.
Minutes later, gunmen opened fire at a nearby checkpoint killing two more policemen.
Since the beginning of the year, at least 200 people have been killed across Iraq in a wave of attacks by suspected insurgents.
There was no immediate claim of responsibility for Friday's attack.
Since the United States completed its pullout last month, militant groups - mainly al Qaeda in Iraq - have stepped up attacks targeting the country's majority Shiites to undermine confidence in the Shiite-led government and its efforts to protect people without American backup.
The Associated Press contributed to this report.
