The report, by the Norwegian Refugee Council's Global IDP Project, warns that unless the return of thousands more Kurdish refugees to their home areas is better regulated, "simmering tensions between the ethnic groups in the region are likely to worsen."
The Global IDP Project, based in Geneva, performed the study as part of its work tracking patterns of internal displacement in numerous countries worldwide.
During Hussein's reign at least 800,000 Kurds and other non-Arabs were forced out of ethnically mixed areas in northern Iraq, including Kirkuk and Mosul. They were replaced with Arab settlers from other parts of the country considered more loyal to the regime.
Many of the Kurdish refugees fled to Kurdish-administered parts of northern Iraq that fell out of Baghdad's control after the 1991 Gulf War. Some 30,000 of those Kurds are reported to have returned home again since Hussein's regime was toppled in April.
Birkenes says Arabs and members of Iraq's Turkoman minority accuse the Kurdish administration of encouraging refugees to return in a deliberate effort to ensure non-Kurdish groups will be outnumbered in the event of a referendum on the future status of the city and the Kurdish region: "The Turkomans and the Arabs in Kirkuk, especially, and also in some of the other governates controlled by the [U.S.-led] coalition and the Governing Council in Baghdad, [say] that the Kurdish regional government is trying to increase its influence in the same way as Saddam Hussein's regime tried during the 1970s, 80s and 90s."
The two main Kurdish factions, whose forces entered Kirkuk as Hussein's forces retreated early last year, now say they control security in the city. Their united Kurdish administration has denied any charges of forcing out Arabs or other groups.
The Kurdish administration says it provides only humanitarian aid to returning Kurdish refugees -- many of whose homes are now occupied by Arab settlers.
But Kurdish leaders also maintain that Kirkuk is a Kurdish city and should be part of a Kurdish region in a new federal Iraq. Some 2,000 Turkomans and Arabs demonstrated in Kirkuk in late December against any effort to incorporate the city into an autonomous Kurdish province. Five people were reported killed in the unrest.
Birkenes says the U.S.-led Coalition Provisional Authority (CPA) is now trying to stem the return of Kurds to Kirkuk in order to lower the tensions: "It seems that the CPA has a kind of two-pronged approach, meaning that they are trying to physically prevent Kurds from entering into Kirkuk and, at the same time, are working politically with the Kurdish regional government and encouraging them not to encourage Kurdish return movements."
He says that the CPA has also requested the Kurdish regional government to stop providing humanitarian assistance until a commission can be formed to mediate property disputes between returning refugees and settlers.
The new report, which was issued yesterday, says that many of the displaced Arabs are now living north of Baghdad in "abandoned army camps and public buildings, most without access to health services, electricity or running water."
The Global IDP Project has been tasked by the UN with monitoring problems with internally displaced people in Iraq since 1988. It is funded by several European governments and foundations and its information is used in part by officials for deciding when asylum seekers can safely return to their home areas.
Birkenes says that -- based on the current report -- the Norwegian Refugee Council will recommend to the Norwegian government not to return asylum seekers from areas like Kirkuk and Mosul until tensions lessen there.