A car bomb struck a market in a Kurdish area in the northern city of Kirkuk on Friday, killing at least eight people and wounding dozens, police said. South of Baghdad, the military said a US helicopter was forced down, leaving two soldiers injured. The attack in Kirkuk, a disputed oil-rich city that has seen a recent rise in ethnic tensions, occurred while the capital remained relatively calm under a driving ban aimed at preventing such attacks during a major Shiite pilgrimage. The blast tore through the stalls as the market was packed with afternoon shoppers buying vegetables and household goods in a predominantly Kurdish area in southern Kirkuk, 290 kilometers north of Baghdad. Police initially said it was a suicide attack, but police Brig. Gen. Sarhad Qader later said it was a parked car bomb. Qader said at least eight people were killed and 45 were wounded.