US Army Col. Ryan Dillon, the coalition spokesman, says all the attackers were killed.
Dillon says today's attack occurred in the area of the northern town of Hawija, one of the last pockets of IS control after the extremists were driven from Mosul earlier this year.
US-backed Iraqi forces have retaken all the major urban areas the extremists once held in Iraq, but IS remains capable of carrying out attacks on civilian and military targets.