"We have seven people killed and 68 others wounded by the three car bomb attacks in Kirkuk in the morning," said a source from Kirkuk police on condition of anonymity because he was not authorized to speak to the media.

The blasts, which occurred around 10:20 a.m. local time (0720 GMT), left at least six vehicles totally charred and caused severe damages to many houses and civilian cars in the neighborhood, the source said.

Earlier in the day, Brigadier General Sarhat Abdul Qader said that the three massive blasts occurred almost simultaneously in the neighborhood of al-Wasitti in southern Kirkuk, some 250 km north of Baghdad.

One of the car bombs ripped through an area near a base of a Kurdish security force, and another struck a police convoy carrying Colonel Ahmed Shamirani, chief of a police force in the city, who was wounded by the attack, while a third car bomb explosion hit a police patrol down the street of the security base, Qader said.

An Iraqi television News footage showed two columns of black smoke rising in southern Kirkuk by two car bombings, and suddenly a mushroom of dense black smoke and a cloud of dust poured into the sky by a third massive blast elsewhere in the same neighborhood.

Earlier, the police put the toll at six killed and 35 wounded, including policemen.

The oil-rich Kirkuk province and its capital Kirkuk City are part of the disputed areas between the Kurds and both Arabs and Turkmans. The area has long been the hotbed of insurgency since the U.S.-led invasion in 2003.