Seized off the streets of Kirkuk or in joint U.S.-Iraqi raids, the men have been transferred secretly and in violation of Iraqi law to prisons in the Kurdish cities of Irbil and Sulaymaniyah, sometimes with the knowledge of U.S. forces. The detainees, including merchants, members of tribal families and soldiers, have often remained missing for months; some have been tortured, according to released prisoners and the Kirkuk police chief.

A confidential State Department cable, obtained by The Washington Post and addressed to the White House, Pentagon and U.S. Embassy in Baghdad, said the "extra-judicial detentions" were part of a "concerted and widespread initiative" by Kurdish political parties "to exercise authority in Kirkuk in an increasingly provocative manner."

The abductions have "greatly exacerbated tensions along purely ethnic lines" and endangered U.S. credibility, the nine-page cable, dated June 5, stated. "Turkmen in Kirkuk tell us they perceive a U.S. tolerance for the practice while Arabs in Kirkuk believe Coalition Forces are directly responsible."

The cable said the 116th Brigade Combat Team, which oversees security in Kirkuk, had urged Kurdish officials to end the practice. "I can tell you that the coalition forces absolutely do not condone it," Brig. Gen. Alan Gayhart, the brigade commander, said in an interview.

Kirkuk, a city of almost 1 million, is home to Iraq's most combustible mix of politics and economic power. Kurds, who are just shy of a majority in the city and are growing in number, hope to make Kirkuk and the vast oil reserves beneath it part of an autonomous Kurdistan. Arabs and Turkmens compose most of the rest of the population. They have struck an alliance to curb the ambitions of the Kurds, who have wielded increasing authority in a long-standing collaboration with their U.S. allies.

Some abductions occurred more than a year ago. But according to U.S. officials, Kirkuk police and Arab leaders, the campaign surged after the Jan. 30 elections consolidated the two main Kurdish parties' control over the Kirkuk provincial government. The two parties are the Patriotic Union of Kurdistan and the Kurdistan Democratic Party. The U.S. military said it had logged 180 cases; Arab and Turkmen politicians put the number at more than 600 and said many families feared retribution for coming forward.

U.S. and Iraqi officials, along with the State Department cable, said the campaign was being orchestrated and carried out by the Kurdish intelligence agency, known as Asayesh, and the Kurdish-led Emergency Services Unit, a 500-member anti-terrorism squad within the Kirkuk police force. Both are closely allied with the U.S. military. The intelligence agency is made up of Kurds, and the emergency unit is composed of a mixture of Kurds, Arabs and Turkmens.

The cable indicated that the problem extended to Mosul, Iraq's third-largest city and the main city in the north, and regions near the Kurdish-controlled border with Turkey.

The transfers occurred "without authority of local courts or the knowledge of Ministries of Interior or Defense in Baghdad," the State Department cable stated. U.S. military officials said judges they consulted in Kirkuk declared the practice illegal under Iraqi law.

Early on, the campaign targeted former Baath Party officials and suspected insurgents, but it has since broadened. Among those seized and secretly transferred north were car merchants, businessmen, members of tribal families, Arab soldiers and, in one case, an 87-year-old farmer with diabetes. A former fighter pilot said his interrogation in Irbil focused in part on whether he participated in the chemical weapons attack on the Kurdish city of Halabja in March 1988, in which an estimated 5,000 people died.

"I think it's about revenge," said the man, who identified himself as Abu Abdullah Jabbouri and who was released last week from the prison in Irbil.

Abdul Rahman Mustafa, the Kurdish governor of Kirkuk province, said the reports of abductions were "not true," although prisoners were often transferred to other provinces to relieve crowding. Jalal Jawhar, who heads the Patriotic Union of Kurdistan in Kirkuk, said some suspects were transferred to prisons in Irbil and Sulaymaniyah with the "complete cooperation" of the U.S. military.

"This is a normal procedure," Jawhar said.

Maj. Darren Blagburn, intelligence officer for the 116th Brigade Combat Team in Kirkuk, acknowledged that Arab and Turkmen detainees were surreptitiously transferred to Kurdish prisons without judicial oversight. He denied any U.S. role in the transfers and said they were necessary because of crowding in Kirkuk's jails.

Blagburn said he and other U.S. officers intervened with Kurdish leaders after discovering the practice nearly a month ago. He said he was "pretty sure" the practice had ended.

"We put a stop to it," Blagburn said, adding: "One of the myths is that it is spiraling out of control and nobody is doing anything about it and nobody cares. That is absolutely not true."

But across an already tense political landscape in Kirkuk, the campaign has deepened a climate of fear and intimidation.

Gen. Turhan Yusuf Abdel-Rahman, the chief of Kirkuk's police force, described the abductions as "political kidnappings" orchestrated by the Kurdish parties and their intelligence arms. Abdel-Rahman, who is Turkmen, said at least four Arabs and one Turkmen were seized last week but that "there may be others." On Sunday, two days after Blagburn's remarks, the U.S. military received reports that nine more Arabs and Turkmens were missing.

Abdel-Rahman said his officers were taking part in the majority of the abductions despite his attempts to stop the practice. He said 40 percent of Kirkuk's 6,120-member police force was loyal to the two Kurdish political parties. Acting on the parties' orders, uniformed officers carried out the abductions using the police department's cars and pickup trucks, he said.

"The main problem is that the loyalty to the police is to the parties and not the police force," said Abdel-Rahman, 41, a career officer. "They'll obey the parties' orders and disobey us."

Abdel-Rahman said he was deeply frustrated. "People ask us about their sons. What should I say to them?"

History of Struggle

The struggle for Kirkuk draws on the city's tortured history. In a policy known as Arabization, President Saddam Hussein drove out thousands of Kurds and replaced them with Arabs from areas to the south. That step was part of a larger strategy to depopulate the region of Kurds, an effort that peaked at the end of the 1980-88 Iran-Iraq war. In all, at least 100,000 Kurds were killed and 2,000 villages destroyed as Hussein took revenge for Kurdish support of Iran during the conflict.

After Hussein's fall, the Kurdish parties seized control of key positions within Kirkuk's security forces, and the Jan. 30 elections put Kurds in control of the provincial government. They have also emerged as the U.S. military's main ally in the fight against Sunni Arab insurgents in the region, providing intelligence, support and manpower.

The U.S. military acknowledged picking up detainees in joint raids with the Kurdish-led police and handing them over. But military officials said the secret transfers were ordered by individual Iraqi police commanders. Blagburn said commanders affiliated with the Kurdistan Democratic Party dispatched detainees to an Irbil prison operated by the party's intelligence arm. Commanders affiliated with the Patriotic Union of Kurdistan sent detainees to their party's facility in Sulaymaniyah, he said.

The State Department cable noted that U.S. commanders had denied complicity in the transfers, contrary to the perceptions of Arabs and Turkmens. "Coalition PR efforts to counter the story have been ineffective," stated the cable, which was written by the U.S. Embassy's regional coordinator.

"What can we do?" asked Jabbouri, the prisoner released last week. "The Americans are with the Kurds, together. They're walking along the same path."

Jabbouri said he was seized during a raid on his house the night of April 30 in the Kirkuk neighborhood of Rashid. A former fighter pilot who now works as a colonel in the Iraqi Interior Ministry, he pleaded with the Iraqi police and their U.S. colleagues that he had been wrongly targeted by them. The Americans, dressed in civilian clothes and flak jackets, ignored him, he said.

Jabbouri said he was seized with three other men, two of them air force veterans. The Americans photographed the detainees at the entrance to the U.S. air base in Kirkuk, then turned them over to the police, he said. Police placed bags over their heads and moved them between what seemed to be houses in Kirkuk and Irbil for several hours before taking them to the main prison the next day, he said.

There, Jabbouri said, he lived with about 50 men crammed into a 19-by-9-foot cell. The prisoners slept on a bare concrete floor. Conditions were so cramped, he said, the men divided the day into shifts. For three hours, half sat cross-legged while the others lay on their sides in rows and slept.

Jabbouri said he was questioned three times. He said he was treated respectfully. But others in his cell were beaten, he said. Some were forced to wear a 130-pound metal jacket and were beaten when they collapsed, he recalled. Jabbouri said that upon his release he met a fellow prisoner who displayed scars from wounds sustained when he was whipped with a wire cable, sometimes heated over a fire.

"Once you go inside, you never think you're going to come out," Jabbouri said.

Najat Hassan Karim, the Kurdistan Democratic Party representative in Kirkuk, denied that prisoners were mistreated. "They are lies," he said of the allegations. "There is no torture." U.S. officers said they had no evidence that any of the detainees had been tortured.

Flood of Complaints

The U.S. military first heard of the abductions in late February as families searching for their missing relatives began to appear at the provincial government seat in the city of Kirkuk. Lt. Col. Anthony Wickham, who heads a team of U.S. military advisers to the provincial government, said he initially thought the crimes were a recurrence of a wave of ransom-motivated kidnappings last year.

"Then it turned into a new twist: We found out our own brothers-in-arms were involved," Wickham said. By mid-April, the complaints "became a flood," he said. Wickham said he became convinced that the security forces were orchestrating the campaign after seeing letters from the prisoners in the north conveyed to their families by the International Committee of the Red Cross.

"Maybe it was naivete on our part, that people would be taken by the police, of all people, to another province," Wickham said. "When we realized what was happening, the first thing we said was, 'Stop. Don't you realize what you're doing, the tensions that you're creating?' The second thing we said was, 'You've got to get them out.' "

Last month, U.S. officers took a list of missing Arabs and Turkmens to the Kurdish parties and asked for their release. The Kurdistan Democratic Party freed 42 prisoners. The Patriotic Union of Kurdistan has yet to free any. With hundreds of prisoners still unaccounted for, many families said their search had become increasingly desperate. In one Kirkuk neighborhood, Arab residents approached a journalist's car to ask for help locating their missing relatives.

"When we go to the Americans, they send us to the police," said Osama Danouk, 24. "When we go to the police, they send us to the Americans, and so on, and so on."

His father, Danouk Latif Jassem, was seized March 2 when U.S. soldiers and Iraqi police stormed into his stationery shop. Jassem, blindfolded and handcuffed, was held for 12 days in the jail of the Emergency Services Unit. From there, his son said, he was taken to the prison in Irbil. Jassem's wife and 12 children have yet to communicate with him, save for two letters he sent through the Red Cross.

"My health is good," he said in one worn letter dated May 17 and folded eight times. "I hope that you don't worry too much about me. This is the will of God."

The family traveled on eight successive Thursdays to Irbil but was barred from visiting him, they said. They sought help from Arab tribal leaders, human rights organizations, the provincial government, the U.S. military and even the Kurdish parties.

"Four months and no one can help us," said Danouk, grabbing the Red Cross letter. "Just this."

U.S. and Iraqi officials said the abuses were an outgrowth of Kirkuk's dysfunctional police force, a product of patronage and partisan loyalties. The head of the Emergency Services Unit, Col. Khattab Abdullah Arif, is a Patriotic Union of Kurdistan loyalist and former Kurdish militia fighter with no previous police experience. The provincial police director general, Sherko Shakir Hakim, most recently worked as a taxi driver. Abdel-Rahman, Kirkuk's police chief, said Hakim refused a central government order to retire two weeks ago after the Kurdish parties promised to pick up his salary.

"With all this, we should be insane," Abdel-Rahman said, smiling darkly.

Abdel-Rahman said he was concerned that the Americans were being duped by the Kurds, who he said have cloaked what is effectively a power grab as a crackdown on the insurgents. Their strategy, he said, is to bolster their alliance with the Americans.

"Unfortunately, they have succeeded," he said.

Blagburn, the intelligence officer, said that even though the Emergency Services Unit is largely responsible for the secret transfers, it continues to provide valuable assistance in the counterinsurgency. Blagburn termed the unit "a very cooperative, coalition-friendly system."

"We know we can drop a guy in there and he'd be taken care of and he's safe," Blagburn said. "That's the reason why the ESU is used most of the time. That's basically the unit we can trust the most."

The State Department cable warned that the abuses by the emergency unit threaten to "seriously undermine [Iraqi government] and Coalition efforts in the region unless procedures are established to enforce Iraqi laws with regard to the transfer of detainees."

As he sat in his house, the fans idle on a scorching day during a blackout, Aissa Ramadan seethed over the seizure of most of his family.

He said they were taken March 17, when U.S. and Iraqi forces arrived at his family's compound in the village of Shahid Faleh, about 20 miles south of Kirkuk. Ramadan's three brothers and two sons were taken, along with his 87-year-old father, Ramadan Taha, who walks with a cane. "I wasn't there," he said. "If I was there, they would have taken me, too."

Three months later, the house still bore signs of the raid: The windows of the mud huts were shattered, closet doors were ripped from the hinges, wedding pictures and a television were broken. Ramadan accused the Iraqi forces of stealing $5,000 from under his father's bed and 450,000 Iraqi dinars ($300) from his mother's pocket. One soldier ripped a gold bracelet off his sister-in-law's wrist, he said. Another hit his mother, in her sixties, in the left shoulder with a rifle butt. Videos of his oldest son's wedding were confiscated.

Last month, Ramadan's two sons were released from the Emergency Services Unit's custody; one said he had been hit so hard in the kidney he was urinating blood. One of Ramadan's brothers is still in the jail. A policeman told the family they could pay $5,000 to get him freed. A friend who works with the police told Ramadan that his father and two other brothers were taken to Sulaymaniyah.

No one has heard from them since their transfer on March 23.

"If you could see our house on any day, you'd see that we're having funerals without the corpses," Ramadan said. "Children are looking for their fathers, wives don't know the fate of their husbands, and mothers are dying 40 times a day."

Ramadan said he had "anger in his heart."

"Tomorrow, I could recruit the entire tribe," he said. "I could block the street in Kirkuk and kidnap 40 Kurds. When you lose patience, you can do anything."