BAGHDAD - As the American military pushes the largely Shiite Iraqi security services into a larger role in combating the insurgency, evidence has begun to mount suggesting that the Iraqi forces are carrying out executions in predominantly Sunni neighborhoods.

Hundreds of accounts of killings and abductions have emerged in recent weeks, most of them brought forward by Sunni civilians, who claim that their relatives have been taken away by Iraqi men in uniform without warrant or explanation.

Some Sunni men have been found dead in ditches and fields, with bullet holes in their temples, acid burns on their skin, and holes in their bodies apparently made by electric drills. Many have simply vanished.

Some of the young men have turned up alive in prison. In a secret bunker discovered earlier this month in an Interior Ministry building in Baghdad, American and Iraqi officials acknowledged that some of the mostly Sunni inmates appeared to have been tortured.

Bayan Jabr, the interior minister, and other government officials denied any government involvement, saying the killings were carried out by men driving stolen police cars and wearing police and army uniforms purchased at local markets. "Impossible! Impossible!" Mr. Jabr said. "That is totally wrong; it's only rumors; it is nonsense."

Many of the claims of killings and abductions have been substantiated by at least one human rights organization working here - which asked not to be identified because of safety concerns - and documented by Sunni leaders working in their communities.

American officials, who are overseeing the training of the Iraqi Army and the police, acknowledge that police officers and Iraqi soldiers, and the militias with which they are associated, may indeed be carrying out killings and abductions in Sunni communities, without direct American knowledge.

But they also say it is difficult, in an already murky guerrilla war, to determine exactly who is responsible. The American officials insisted on anonymity because they were working closely with the Iraqi government and did not want to criticize it publicly.

The widespread conviction among Sunnis that the Shiite-led government is bent on waging a campaign of terror against them is sending waves of fear through the community, just as Iraqi and American officials are trying to coax the Sunnis to take part in nationwide elections on Dec. 15.

Sunnis believe that the security forces are carrying out sectarian reprisals, in part to combat the insurgency, but also in revenge for years of repression at the hands of Saddam Hussein's government.

Ayad Allawi, a prominent Iraqi politician who is close to the Sunni community, charged in an interview published Sunday in The London Observer that the Iraqi government - and the Ministry of Interior in particular - was condoning torture and running death squads.

The allegations raise the possibility of the war being fought here by a set of far messier rules, as the Americans push more responsibility for fighting it onto the Iraqis. One worry, expressed repeatedly by Americans and Iraqis here, is that an abrupt pullout of American troops could clear the way for a sectarian war.

One Sunni group taking testimony from families in Baghdad said it had documented the death or disappearance of 700 Sunni civilians in the past four months.

An investigator for the human rights organization said it had not been able to determine the number of executions carried out by the Iraqi security forces. So far, the investigator said, the evidence was anecdotal, but substantial.

"There is no question that bodies are turning up," said the investigator, who agreed to speak on the condition of anonymity, citing safety concerns. "Quite a few have been handcuffed and shot in the back of the head."

As an example, the human rights investigator said that the group had been able to verify that a number of Sunni men taken from the Baghdad neighborhood of Huriya and shot to death last August. Relatives of the dead told the group that more than 30 men had been taken from their homes by the Iraqi police in what appeared to be a roundup of Sunni males.

In the Iskan neighborhood in Baghdad, the human rights group said it had confirmed that 36 Sunni men had been abducted and killed in the neighborhood in August. Sunni groups say the men were taken from their homes by men who identified themselves as intelligence agents from the Interior Ministry.

"The stories are pretty much consistent across the board, both in the manner that the men are being abducted and in who they say is taking them," the human rights investigator said.

More than 15 Sunni families interviewed for this article gave similar accounts of people identifying themselves as Iraqi security forces taking their relatives away without warrants. The families said that most of those said to have been abducted were later found dead.

On Nov. 12, according to the Samarraie family in Gazalia, a Baghdad neighborhood, a group of masked men identifying themselves as agents of the Interior Ministry broke down the family's door. Outside, the family members said, was a line of white pickup trucks with machine guns mounted on them.

The men in masks said they were looking for Yasir, 36, one of the Samarraie brothers, the family said. They took him away.

"We are intelligence people from the Ministry of the Interior," one of the men said, according to Yasir's wife, Wuroud Sami Younis.

A few days later, the police found Yasir's body in an empty field a couple of neighborhoods away. His skull was broken, and there were two bullet holes in his temple, family members said. Officials at the city morgue confirmed Mr. Yasir's death.

"The government is trying to terrorize and dominate the Sunni people," said Yasir's brother, Shuhaib.

The claims of direct involvement by the Iraqi security services are extremely difficult to verify. In a land where rumor and allegation are commonly used as political weapons, the truth is difficult to distill.

Mr. Jabr, the interior minister, acknowledged that many civilians were being killed in Baghdad and around Iraq, and that some of them were being killed for sectarian reasons. "When we have cases like that, we investigate them, and if we can find the culprits we arrest them," he said.

The chief suspects, according to Sunni leaders, human rights workers and a well-connected American official here, are current and former members of the Badr Brigade, the Iranian-backed militia controlled by the Supreme Council for the Islamic Revolution in Iraq, a principal part of the current government. Since the fall of the Hussein government in April 2003, Badr gunmen are suspected of having assassinated dozens of its former officials, as well as suspected insurgents.

Since April, when the Shiite-led government came to power, Badr fighters have joined the security services, like the police and commando units under the control of the interior minister, Mr. Jabr, who is also a senior member of the Supreme Council.

With Badr gunmen operating inside and outside the government, the militia can act with what appears to be official backing. It is not clear who is directing the security services, the government officials or the heads of the militias.

"The difference between the Ministry of the Interior and the Badr Brigade has become very blurry," the human rights investigator said.

"You have these people in the security services, and they have different masters," said the American official in Baghdad. "There isn't a clear understanding of who is in charge."

The alarm in the Sunni community is so great the Um al-Qura Mosque, one of the largest temples in Baghdad, has begun documenting cases of allegations of executions and abductions. Mazan Taha, who is overseeing the project, said he has compiled the names of some 700 Sunni men who have disappeared or been killed in the past four months.

In one Sunni neighborhood, Sababkar, residents said the Iraqi Army surrounded the neighborhood and took away 11 of its Sunni men in July. Most of the bodies were found the next day; television stations here showed pictures of bodies that had been burned with acid and drilled with holes by electric drills. Most of the men had been shot in their temples.

"How did these killers get police uniforms?" Mr. Taha asked of the details surrounding many of the killings. "How was it that they were operating freely after curfew? That they had police cars?"

Each day, Sunni families with little faith that the Shiite-led government will help them line up at Mr. Taha's office instead, to tell of family members who have been killed and disappeared.

"They took three of my sons!" wailed Naima Ibrahim, waving three government-issued identification cards, as Mr. Taha quietly wrote the information down. "They took three of my sons!"

The grief in Baghdad's Sunni neighborhoods has begun to spill onto the streets.

On Friday, hundreds of Iraqi Sunnis marched through the Amriya neighborhood to protest the killing of a prominent Sunni leader and three of his sons last Wednesday. Witnesses said the killers were wearing Iraqi army uniforms and came in the middle of the night, when the curfew has been strictly enforced. The Sunni leader, Kadhim Surhid, was buried, but much was unclear.

"They killed them in their beds," said Jama Hussein, a friend who attended the funeral. He jutted his palms out from his body. "I myself carried them from their beds."

Copyright 2005 The New York Times Company

###