Police chief Col Bestoon Rasheed today said that the bomber drove his explosives-laden vehicle into a security checkpoint in the town of Dibis.
The town is located near the city of Kirkuk, 290 kilometres north of Baghdad.
Rasheed added that 15 other people were wounded in the attack. Civilians were among the victims, but a breakdown of the casualties was not immediately available.
No one immediately claimed responsibility for the attack but suicide bombings are a hallmark of an al-Qaida's breakaway branch that operates in Iraq.