At least five people were killed in a car bombing in a Kurdish area in the disputed northern city of Kirkuk Iraqi police said.

Police spokesman Col. Sarhat Qadir said Thursday's attack occurred about 8 p.m. in a restaurant-packed market area in the Rahim Awaa district. Qadir says 30 people also were wounded.

Several bombings have raised concern about the readiness of Iraqi forces to take over their own security more than a month after U.S. troops withdrew from urban areas as part of a plan to pull out entirely by the end of 2011.

Tension between Kurds and Arabs over oil and land, particularly around the northern, oil-rich area of Kirkuk, has emerged as a major threat to Iraqi stability.