Officials in Iraq are investigating a suicide bombing that left at least seven dead and 12 wounded.<br/> <br />Charred wreckage is all that remains after police say an explosive-laden vehicle rammed into a checkpoint west of Kirkuk.<br/> <br />The city lies on the front line of a dispute between the Shi'ite-led central government in Baghdad and ethnic Kurds.<br/> <br />The Kurds want the city to be incorporated into their autonomous region in the north of the country.<br/> <br />No one has immediately claimed responsibility for the attack.
