A booby-trapped minibus went off around noon near a Shia mosque in downtown Kirkuk, some 250 km north of Iraq's capital Baghdad, a local police source told Xinhua on condition of anonymity.
The huge blast struck dozens of people seeking refuge in the Shia mosque. They fled their homes in the city of Tal Afar in northern Iraq in the wake of advances by extremist Sunni insurgents, the source said.
Three children were among the dead and many of the wounded were women, the source added.
The security situation began to drastically deteriorate in Iraq June 10 when bloody clashes broke out between Iraqi security forces and hundreds of militants of the Islamic State (IS) insurgent group who took control of the country's northern city of Mosul
The IS later seized swathes of territories after the Iraqi security forces abandoned their posts in Nineveh and other predominantly Sunni provinces.