KIRKUK, Iraq — A surge in violence in this oil-rich city divided among Kurds, Sunni Arabs and Turkmens vying for power has alarmed Iraqi officials amid intensifying sectarian warfare in central and southern Iraq.
Kirkuk has been contested ground since the 2003 U.S.-led invasion of Iraq, when Kurds displaced by Saddam Hussein and previous Sunni Arab-dominated governments began returning to their former homes.
Sunni Arab political leaders believe the Kurds are trying to push them out of the northern city and intend to annex it to the Kurdish region of Iraq.
Kurds believe that Kirkuk is part of a greater Kurdistan and that they have a historic claim to the city.
American officials have encouraged the groups to work out their differences politically. And by Iraq's standards, Kirkuk has remained relatively peaceful. But the number of bombings, assassinations and other attacks has risen sharply, both in Kirkuk and smaller cities around it, Iraqi officials say.
So far this month, at least 84 people have been killed in Kirkuk and surrounding areas.
A new report by the International Crisis Group, a Brussels-based think tank, calls on the international community to step in to resolve the "mounting tensions" in Kirkuk or risk full military conflict in the city.
The United Nations should begin to negotiate a compromise under which Kirkuk and the surrounding countryside would become an area separate from the Kurdish region to the north, the report says.
Kurdish-dominated security forces have been the targets of several deadly attacks that officials believe were carried out by Sunni Arab insurgents.
Car bombers and snipers have also hit police and army checkpoints and patrols outside the city.
On Wednesday, six police officers and four civilians were wounded when a roadside bomb was detonated near a security patrol in southern Kirkuk.
In response to the rising violence, the Iraqi army announced that it had begun an operation targeting insurgents in Rashad, west of Kirkuk.
The offensive was planned by Iraqi forces, an Iraqi army official said.
"This region has lately witnessed escalations of armed attacks against the security forces and Iraqi civilians," the official said.
The official, who asked that his name be withheld because he feared for his family's safety if he was publicly identified, said Iraqi and American troops were participating in the offensive.
