ERBIL, Iraq—The policies and tactics of Kurdish authorities are exposing minority groups in northern Iraq to “;another full-blown human rights catastrophe”; unless the minorities receive better protection, according to a report released Tuesday by Human Rights Watch.

Members of the minority groups are being singled out by extremist insurgent groups and also are caught in the middle of a struggle for land and resources between Arabs and the central government on one hand and leaders of Iraq's semiautonomous Kurdish region on the other, said the report, which was released in the Kurdish region's capital, Erbil, and focused on Christians, Shabaks and Yazidis in Nineveh province.

“;When you talk about wiping out a whole community that has been there since antiquity, it's a looming catastrophe,”; said Joe Stork, deputy Middle East director at Human Rights Watch, which is based in New York.

The report is particularly critical of the policies and tactics pursued by Kurdish authorities who control Nineveh's disputed territories through the heavy presence of their security forces and political party offices. The report describes how the Kurdish government has sought to repress minorities, subsume the identity of Shabaks and Yazidis into that of Kurds and sow rifts within the groups with bribes and patronage while suppressing dissent through violence, torture, arrests and killings.

The U.S. military has recognized the Arab-Kurdish conflict in northern Iraq as the main driver for continued instability in Iraq. The disputed territories extend from Sinjar in Nineveh in northwestern Iraq to Mandali in Diyala province in the east and include the oil-rich city of Kirkuk.

After a series of bombings in July and August against minorities in Nineveh that killed at least 143, wounded scores and flattened villages, the American military commander in Iraq, Gen. Ray Odierno, announced plans to deploy U.S. troops along with members of the Kurdish pesh merga force and the Iraqi army in the disputed areas to stop groups linked to al-Qaida from exploiting friction between Arabs and Kurds.

With the exception of occasional joint operations and meetings between pesh merga and Iraqi army officers that occur because of American insistence, no progress has been made in deploying the joint forces in the disputed areas or getting the Kurds and the central government to cooperate on security in a meaningful way, said Sheik Jaffar Sheik Mustafa, the minister of the pesh merga, who is the Kurdish region's equivalent of minister of defense.

Mustafa said the combined forces would be based at combat outposts throughout the north and would conduct joint raids and patrols and staff checkpoints. He said the Kurdish authorities had agreed to the idea but that opposition was coming from Baghdad and the Arab-led provincial government in Nineveh, which see the arrangement as an infringement on their sovereignty and want Kurdish troops to retreat from the areas they occupy outside their region's 1991 border.

“;I think this joint force is crucial at this juncture,”; Mustafa said.

A senior American official in Kirkuk said he was optimistic that the joint force would ultimately become functional.

A representative of the U.S. Embassy in Baghdad said that “;in tandem with an ambitious push to improve security for all in the province, including embattled minorities,”; American officials were working to resolve a political standoff between Sunni Arabs and Kurds in Nineveh's provincial capital, Mosul, that has exacerbated the situation.

After its victory in the provincial elections in January in Nineveh, a Sunni Arab-led coalition excluded the second-place Kurdish coalition from all senior posts in the new local government and demanded that the pesh merga leave the Nineveh areas they controlled. In response, the Kurds boycotted meetings of the provincial council and used force to prevent the Arab governor and other senior officials allied with him from entering areas in Nineveh controlled by Kurdish forces.

Mustafa said the joint security forces must include Americans in order to secure the area and carry out Article 140 of the Iraqi Constitution, which outlines the mechanism for resolving the fate of disputed territories. Kurds are clinging to it, but Arabs reject it.

“;We will not give up one inch of the areas that we occupy until Article 140 is implemented,”; Mustafa said.

He dismissed the findings of the Human Rights Watch report as “;false.”; He said that there might have been violations committed by individual Kurdish security officers against minorities in Nineveh but that this did not reflect the policy of the Kurdistan Regional Government.