Violence against Kurds has escalated in recent days, officials say. The offices — and officials — of Kurdish political parties have been attacked. Insurgents fired on a truck carrying Kurdish peshmerga fighters. And at least one Kurd was said to have been beheaded in Mosul, a largely Sunni Arab city.

"They are trying to ignite the flames of sedition between Arabs and Kurds," Khasro Gouran, Mosul's Kurdish deputy provincial governor, said by telephone from Mosul. "They want the Kurds to react and the peshmerga to come in (from outside Mosul) so there would be sectarian strife in the city."

"They won't succeed because the Kurdish leadership is aware of their plans," Gov. Duraid Kashmoula, an Arab, said of the insurgents.

The Kurds are not the only ones under attack. During the latest bout of violence, masked men have stormed police stations, looting and burning some. They've also set up their own checkpoints and set cars ablaze, prompting the Americans to launch military operations to oust fighters from their stronghold in the city.

Gouran said that in recent days three Kurds were killed, including at least one whose decapitated body was discovered with the head placed on the back.

The two main Iraqi Kurdish parties are mostly secular U.S. allies that have a bloody history of animosity with some militant Islamic groups and Baath Party loyalists, both believed to be active in the Mosul insurgency. The parties have long been targets.

The Kurdish minority generally lives in peace with Mosul's Arab majority, although land and property disputes have in the past created some tensions.

When the militants overpowered Mosul's police force, which U.S. and Iraqi officials say is infiltrated by insurgents, the local government called in reinforcements, some of which came from the mostly quiet Kurdish region.

Gouran said some of the Iraqi National Guard reinforcements rushed to the city came from the Kurdish provinces of Dohuk and Irbil. He said many of their members were former peshmerga, a term that refers to the Kurdish militia that fought former Baghdad governments.

In addition, Kurdish political parties called in peshmerga fighters to guard their offices. The Kurdish militia proved harder for insurgents to overpower than the police — in some cases killing or capturing their attackers.

The solution offered its own problems: The fact that many of the National Guardsmen were Kurds and former peshmerga members didn't sit well with some of the city's Arab residents.

Kurdish and Arab officials took pains to stress that National Guardsmen were members of Iraq (news - web sites)'s security forces regardless of their ethnicity or their religion and that no peshmerga fighters were patrolling the streets.

"The Kurds have no intention to take over Mosul or to `Kurdicize' it," Gouran said. "The relationship between Kurds and Arabs in Mosul is strong."

Such assurances fail to ease the concerns of some.

"There has been an escalation in armed attacks against the Kurds and this proves that the Arabs don't agree to let the Kurds control the situation in the city, " said Salem Ghanim Aziz, an Arab resident.

He said that having Kurdish forces could complicate matters, arguing that Arab residents might want to take revenge against the Kurdish fighters from the north that some blame for taking part in the looting that swept through Mosul when it fell during last year's U.S.-led invasion.

"This is an Arab city and we don't accept strangers," said another Arab resident, who identified himself only as Abu Omar. He said he doesn't accept the presence of Kurdish National Guardsmen any more than that of the militants.

Some Kurdish residents said they heard Arab neighbors gloating over recent attacks on the Kurdish parties.

Officials say such sentiments are not widespread and mostly come from Arabs who belonged to the former regime, pointing to Arab-Kurdish intermarriages and amicable relations in the city.

"People say that the Kurds have ethnic designs on the city," said an Arab provincial council member who didn't want his name used for fear of retaliation. "But some of these people have Wahhabi thoughts and others are the disadvantaged members of the former regime who wear the mask of Arab nationalism."

Similarly, he said, some were circulating rumors that other security reinforcements dispatched from Baghdad were Shiites coming to rule over the Sunni majority.

He said the reinforcements were only trying to "prevent Mosul from becoming another Fallujah."

Many in Mosul say they are tired of the violence that has shattered the normalcy of their lives and restricted their movement under a curfew imposed on the city.

One Arab resident who asked that his name not be used said he wanted calm to return to Mosul, be it at Kurdish or Arab hands.

"Don't they say this is a unified Iraq? Let them come from the north or the south as long as they restore security," he said. "Let's forget this talk about ethnicity and religion."

"We're living in hell," he said. "We want to able to go out to the market. We're sick of this."