About 6,000 non-Iraqi security contractors are operating in Iraq. During nine months in 2004-05, contractors reported firing into 61 civilian vehicles; no one was ever prosecuted. Security analysts say it is likely that such incidents are vastly underreported.

Security contractors supporting the U.S. effort in Iraq regularly shoot into civilian cars with little accountability, according to a News & Observer analysis of more than 400 reports contractors filed with the government.

In the documents, which cover nine months of the three-year-old war, contractors reported shooting into 61 vehicles they believed were threatening them. In just seven cases were Iraqis clearly attacking -- showing guns, shooting at contractors or detonating explosives.

There was no way to tell how many civilians were hurt, or how many were innocent: In most cases, the contractors drove away. No contractors have been prosecuted for a mistaken shooting in Iraq.

"What you've done is privatize the fog of war," said Peter W. Singer, an expert on military contracting with the Brookings Institution in Washington.

There are thought to be about 20,000 non-Iraqi civilian contractors supporting a range of U.S. efforts, including about 6,000 security contractors. According to Department of Labor statistics, more than 400 U.S. civilians have died there.

One of the biggest security contractors is Blackwater Security Consulting of Moyock, N.C. The News & Observer began reporting on the industry after four Blackwater men were killed and mutilated in Fallujah in 2004. At least 22 Blackwater contractors have died in Iraq, most in ambushes.

The activities of security contractors have been difficult to quantify, though they are a major force on the ever-changing battlefield. Until now, only a few of their "serious incident reports" to U.S. authorities had been released. The nearly 800 pages that The N&O received this week are the first extensive sampling of contractors' accounts of Iraq's chaos.

The documents include stories of a contractor team shooting at a car in the morning and another in the evening, U.S. forces firing at contractors and contractors shooting at one other.

The government released reports only for nine months ending last April. They detail more than 80 attacks against security contractors that resulted in 48 contractor injuries and 14 deaths. The Pentagon removed the names of the contractors and companies, citing security concerns.

Contractors use standard rules of escalating force for dealing with threats on Iraq's jammed roads:

A gunner in the rearmost vehicle gestures for cars behind him to stop and stay back. If one moves closer, he waves it back again, then points a flashlight. If it keeps coming, warning shots are fired over the top of the suspect vehicle, then into the engine. If that doesn't work, he can shoot to kill.

Here's the narrative from a typical shooting report:

"1 warning shot fired in a safe direction at a black OPEL that refused to adhere to the [private security detail] signals [big torch and hand signals] to stay back. After 1st warning shot car accelerate. When he accelerate we made another 2 warning shots, no reaction from driver we had to open fire directly in to that car using AK[-47 assault rifle] and PKM [machine gun]. The car was stop after we made 23 shots from PKM and 9 shots from AK. Driver ... survived."

Because the reports are voluntary, experts say they probably represent only a fraction of such incidents, and cases in which contractors broke laws or rules are unlikely to be reported.

"If you've got 60 cases where contractors shot into cars, there are probably 600," said James Yeager, a Camden, Tenn., arms trainer whose team shot at cars half a dozen times during his 11 months as a security contractor.

But Doug Brooks, head of the International Peace Operations Association industry group, said he thinks attacks are underreported by perhaps 50 percent.

Whatever the number of shootings, it's likely fewer than similar shootings by U.S. troops. Stars and Stripes reported last week that a military study of an eight-week period late this winter indicated that soldiers killed about 30 Iraqis who drove too close to checkpoints or military convoys.

Hundreds of soldiers in Iraq have been prosecuted under military justice for offenses ranging from drinking to murder. No contractors have been prosecuted for any crimes, Singer and Brooks said.

The advent of civilian security contractors and insurgents who look like civilians has made it hard for anyone on the battlefield to figure out who's who.

The reports paint a picture of such threats as ambushes, suicide car bombers maneuvering to get close, roadside bombs and the possibility of being shot by U.S. troops.

About half the reports involve security contractors. The rest detail incidents involving construction contractors working on projects such as power, water and sewer plants and schools. These list more than 60 kidnappings and 25 murders of Iraqi workers by insurgents trying to stop reconstruction projects.

The difference between living and dying -- for contractors, their clients, insurgents and innocent civilians -- can hinge on decisions that security contractors make in seconds.

"On one side, you've got insurgents who are melting into the civilian population, so you don't know you're being attacked until the actual point of the attack," said Singer, the Brookings expert. "The flip side is, the contractors are often not very well marked, and for the local civilian driving along, sometimes it's very clear they're coming into a contractor convoy; other times it's not."

None of the reports released indicate the rules of escalating force were broken. "You're not going to see those reports," said Yeager, the former contractor. "No one is going to file them."

Yeager said all shootings that he knew of were justified. "The Iraqis knew exactly what cars not to drive up to," he said. "If a guy breaks away from the pack and keeps coming, he knows what's going to happen, and he's either going to try to detonate a bomb, or rake us with gunfire."

Brooks said contracting industry groups are commissioning a radio and newspaper advertising campaign to reinforce to Iraqis what they should do when they see a civilian convoy. The U.S. military is planning a similar campaign, Stars and Stripes reported.