Once united in opposition to Saddam Hussein's brutal oppression against them, Iraq's Shiites and Kurds appear increasingly divided over how to share the spoils of the new Iraq.
Nowhere is that tension more evident than in this oil-rich city in northern Iraq, which many residents fear is about to explode into violence between Kurds and the mainly Shiite Turkmen.
"We are sitting on a barrel of TNT and it will take only one small flame to blow up the whole place," says Yehyia Abdullah, whose shop was looted by a Kurdish mob last week.
The long-simmering friction between Kurds and Turkmens here is taking a sectarian turn, with thousands of Shiite militiamen recently arriving to protect the Turkmens and Arab coreligionists against Kurdish hopes to incorporate Kirkuk into their sphere of influence in the north.
Shiite-Kurdish tensions also lay behind the refusal by five key Shiite members of Iraq's Governing Council to sign an interim constitution on Friday. The document was hammered out in a series of marathon sessions a week ago and is due to last until a permanent charter is created.
The Shiites, prompted by Ayatollah Ali Sistani, the leading Shiite cleric in Iraq, opposed a clause that the Kurds had managed to include that calls for a referendum to approve a permanent constitution next year. The clause says that the referendum would fail if two-thirds of the population of three provinces votes against the constitution. That effectively gave the Kurds, who control three provinces in northern Iraq, a veto over the permanent charter.
Shiite council members conferred with Sistani in Najaf over the weekend apparently and were apparently successful in changing the cleric's mind so the signing ceremony can proceed Monday. Any further delay could jeopardize US plans to transfer sovereignty to Iraqis on June 30.
"The news is very good and tomorrow everything will be clear," Mowaffak al-Rubaie, a Shiite council member said after meeting with Sistani. "We are glad that the grand ayatollah understood our position."
In Kirkuk, the unexpected split in the Governing Council has merely exacerbated the deepening distrust between Kurds and the mainly Shiite Turkmens.
"The Shiites have no right to deny us our rights. My father was killed by Saddam and we reject living under another tyranny. Even if there's a sea of blood, we won't give up Kirkuk," says Najat Jumaa, a shopkeeper in the city's Kurdish district of Tebeh.
At the root of Kirkuk's problems is the question of who is in the majority, and, therefore, who has the right to control the city - and its massive oil wealth. Kirkuk sits on the largest oil field in northern Iraq, with 10 billion barrels in proven oil reserves.
The true demographic composition of this city vanished long ago in a Baathist legacy of manipulated census figures, deportations, mass resettlement programs, and forced identity changes.
Still, that reality fails to stop Kurdish and Turkmen officials from reeling off conflicting statistics and historical claims to back their respective claims to be the largest. "The Kurds used to represent two-thirds of the population here and the other third was composed of Turkmens, Assyrians, Jews, and Arabs," says Jalal Jawhar, the head of the Kirkuk branch of the Patriotic Union of Kurdistan, one of the two leading Kurdish political organizations.
Of Kirkuk's estimated population of a little more than 700,000, according to the last census under the Baathist regime in 1997, Kurds make up 43 percent, he says.
But Turkush Oglu, an official with the Iraqi Turkmen Front, disagrees. "I don't want to exaggerate, but the Turkmens in Kirkuk are about 60 to 65 percent of the population." Mr. Oglu adds that there are some 3.5 million Turkmen in Iraq - a figure disputed by many who put the true number closer to 600,000.
Adding to the murky demographic picture is the deportation under Hussein's regime of thousands of Kurds and Turkmens from Kirkuk and their replacement by Sunni and Shiite Arabs from the south. Entire city districts and surrounding villages were cleansed of their Kurdish and Turkmen population as part of Hussein's attempts to Arabize the city. In addition, many Kurds and Turkmen were compelled to adopt Arab identity so they could purchase property and improve their employment opportunities.
With the removal of the Baathist regime, thousands of Kurds and Turkmens are returning to Kirkuk to lay claim to their former homes, deepening the city's already complex demographics.
A proposed census in the coming months may put to rest the population dispute, but relations are likely to remain cold until then. And concern that those tensions will spill over into violence has grown with the arrival of several Shiite militias here in recent weeks.
They include the Army of the Mahdi, the militia of the firebrand cleric Muqtada Sadr; the Badr Brigades, the military wing of the Supreme Council for the Islamic Revolution in Iraq; Iraqi Hizbullah; and the Dawa Party.
At the start of the month some 2,000 militiamen and -women from the Army of the Mahdi staged a march through Kirkuk.
Kurds viewed the march as a provocative demonstration of Shiite force. The next day, some 100 Kurds ransacked the headquarters of the Iraqi Turkmen Front and looted shops owned by Turkmens and Arabs.
"It's a bad sign and makes us uncomfortable," says the PUK's Mr. Jawhar, referring to the march. "We are trying to build a new Iraqi Army so why do we have to have this Army of the Mahdi. It creates worries for everyone."
However, Shiite officials say they have no intention of clashing with the Kurds. "We are Muslims and we have an army, and armies must march to show their strength. But we didn't make the march against the Kurds," says Sayyed Abdel-Fatah Al-Mussawi, the representative in Kirkuk for Sadr.
Wearing the black turban of the Sayyed, the term given to a direct descendant of the Prophet Mohammed, Mussawi says that the Army of the Mahdi includes Arab, Kurdish and Turkmen Shiites and its numbers are growing.
"The march was only the first," he says. "There will be more marches as more people join us." Jassem Mohammed, a Shiite Turkmen who owns a cigarette stall, says that he joined the Army of the Mahdi out of loyalty to Ayatollah Mohammed Sadeq al-Sadr, father of Muqtada who was killed by Hussein's regime in 1999 and is widely revered by Iraqi Shiites.
"We have always lived peacefully with Arabs and Kurds in Kirkuk," he says. "But the outsiders are the ones making trouble now." Outsiders? "The Kurds," he mutters, looking over his shoulder.
Some Kurdish officials say that Iran is backing the Shiite presence in Kirkuk as a bulwark against Kurdish attempts to control the city. Iraq's neighbors - Iran, Syria and Turkey - oppose Kurdish autonomy, fearing it will inflame their own sizable Kurdish populations.