A car bomb exploded Wednesday near a government security convoy in the northern oil city of Kirkuk, killing at least 11 guards and wounding about 20 other people, police said.
The city is the center of Iraq's vast northern oil fields and the focus of an ethnic power struggle. The majority Kurds want to incorporate the area into their self-ruled northern region, and other ethnic groups want to remain under central government control.
The parked car exploded around 4 p.m. as a four-vehicle convoy of the state-owned Northern Gas Company was driving by, said police spokesman Brig. Gen. Sarhat Qadir.
All the dead were members of a government security agency that provides guards to the gas company. The wounded included 13 guards and eight civilians, Qadir said.
Several shops, buildings and private cars were also damaged in the explosion.
One of the wounded guards from the convoy, Salman Hadi, 38, said the group was returning home when the blast occurred, hurling him from the vehicle.
"When I looked up around me, I saw two bodies of my friends," Hadi said from his bed at the Kirkuk Hospital.
Al-Qaida and other extremist groups operate in northern Iraq and have all used car bombings as a tactic.
Police: Hallmarks of al-Qaida
No group claimed responsibility for the attack but police Brig. Turhan Youssef said the initial investigation showed the explosion had the hallmarks of al-Qaida.
"Today's attack showed that the security forces are not able to completely prevent terrorist attacks," he said. "Al-Qaida wants to spread instability whenever and wherever they have the chance to do so."
In December, a suicide bomber killed at least 55 people in a packed restaurant near Kirkuk where Kurdish and Arab leaders were trying to reconcile political differences.
Kirkuk, located 180 miles north of Baghdad, and the surrounding Tamim province did not take part in provincial elections in January because of the simmering tensions and because the different ethnic groups could not agree on a power-sharing formula.
Kurds make up an estimated 52 percent of Kirkuk's population. Arabs represent 35 percent. Turkomen, ethnic Turks with close ties to Turkey, make up about 12 percent.
The Kurds' concerns are partially rooted in the community's experience under Saddam Hussein, when tens of thousands of them were killed, and more than 1,100 of their villages were razed as part of a campaign to move Arabs into the area.
Wednesday's bombing comes at a time of political tension among the area's Kurdish, Arab and Turkoman populations.
The Kirkuk area didn't take part in the Jan. 31 provincial elections because the groups could not agree on a power-sharing formula. A parliamentary committee was set up to try to broker a deal to allow for elections later.
The committee was supposed to finish its work by the end of March, but the provincial council on Wednesday agreed to extend its mission for two more months, until the end of May.