Suicide bombers have detonated cars packed with explosives in northern Iraq, killing at least 15 people in Kirkuk and four others in the town of Tuz Khurmatu.

In Kirkuk, officials say one of the blasts Wednesday struck outside the offices of the Kurdistan Democratic Party. A separate bomb exploded nearby. More than 100 people were wounded in those attacks.

There was no immediate claim of responsibility for the bombings, which come amid heightened ethnic and sectarian tensions in Iraq.

Also Wednesday, hundreds of mourners gathered for the funeral of influential Sunni lawmaker Ifan Saadoun al-Essawi, who was killed Tuesday by a suicide bombing in Iraq's western Anbar province.

Al-Essawi, a member of the Sunni-backed Iraqiya bloc, was one of the key founders of a group of Sunni tribal militias who joined forces with the U.S. military to fight al-Qaida in 2006.