The statement gave no further details.
Four car bombs exploded on Sunday in apparently coordinated attacks in the oil city of Kirkuk, killing 10 people. The US and Iraqi troops were seen patrolling the city as helicopters hovered overhead after the attacks.
Nearly 60 US soldiers have been killed in Iraq this month, a toll that, at the current rate, threatens to make October the deadliest month for US forces since January 2005.
American commanders have attributed the rise to a surge in violence during the holy month of Ramadan and to more aggressive US operations in Baghdad against sectarian death squads.
REUTERS SAM VV2104