Rubble surrounds the Kurdish PUK Party's offices in Kirkuk after a car bomb explosion here killed at least three people.

Several others were injured in the blast.

Police have also confirmed that in a separate attack in Kirkuk, one Kurdish security guard was killed as a second car bomb targeted a convoy of Kurdish fighters.

A third blast around 67 km south of Kirkuk killed another member of the Kurdish security forces.

No group has yet claimed responsibility for the blasts.

Iraq has grown more volatile as the civil war in neighboring Syria strains fragile relations between Sunni and Shi'ite Muslims, and increases tension in the country's largely Kurdish north.