Ten policemen were killed and at least 20 were wounded Wednesday afternoon when a parked car bomb targeted a passing convoy in the disputed northern city of Kirkuk, police said. Police spokesman Brig. Gen. Sarhat Qadir said all those killed were policemen working as security guards for the state-owned Northern Gas Company. The spokesman said the bomb went off on a street in a southern neighborhood of Kirkuk as the convoy belonging to the gas company was passing by. He said that 12 policemen and eight civilians were among the wounded. Kirkuk is a northern oil city where Arabs, Turkomen and Kurds are competing for power. It lies 180 miles, or 290 kilometers, north of Baghdad.