Police say at least 55 people were killed and 120 wounded.
The attack struck a popular restaurant where Kurdish officials were meeting with Arab tribal leaders. The tribal leaders had been scheduled to meet with President Jalal Talabani after the lunch to discuss ways to defuse tensions among Arabs, Kurds and Turkomen in the Kirkuk area.
The restaurant was also filled with families celebrating the religious holiday of Eid al-Adha. That prompted one of the tribal leaders at the luncheon to question how "a group like al-Qaida claiming to be Islamic plans to attack and kill people on sacred days.''
Kirkuk is located in the center of Iraq's northern oil fields. While it has seen fewer attacks than other regions such as Baghdad, ethnic groups with rival claims to the city have been wrangling over control for years.
(Copyright 2008 by The Associated Press. All Rights Reserved.)