The fighting began after a coalition patrol discovered a roadside bomb in the Hamaniyah section of Ramadi, and two men fled to a house, where they took up positions on the roof, the military said.

As coalition forces removed the bomb, the suspected insurgents opened fire on the U.S. Marines, who fought back with machine guns and tanks, the statement said.

Afterward, coalition forces searched the house and found the six bodies, the military said. Another female also was wounded but refused treatment, it said.

One of the gunmen may have been wounded and removed from the scene by other militants, the statement said, adding that there were no coalition casualties.

The military quoted residents as saying the building "was a known anti-Iraqi force safe house."

Ramadi, 70 miles west of Baghdad, is located in Anbar province, where many Sunni-Arab insurgent groups are based. It has been the scene of some of the fiercest fighting between Marines and insurgents.

"In a very tragic way, today reminds us that insurgents' actions throughout Iraq are felt by all," said Marine Lt. Col. Bryan Salas, a military spokesman. "Efforts are under way to coordinate and offer available assistance to surviving family members."

"Only a fraction," Russert repeated, before also pointing out that Hadley's "own book, Victory in Iraq, says al Qaeda makes up the smallest enemy group."

Russert asked, "Why does the president keep bringing up 'al Qaeda, al Qaeda, al Qaeda,' when your own military and your own reports say that they're the smallest component of the enemy?"

"Because it's true, Tim," Hadley responded.

Russert then asked, "It's true, what?"

"It's true," Hadley insisted. "If you look at what Zarqawi said, who was the lead al Qaeda operative in Iraq, he articulated very early on a strategy for provoking sectarian violence by attacking Shi'a so they, in turn, would attack Sunni. This was part of their strategy to sow chaos, to thwart the advance of democracy and make Iraq a safe haven for terror."

Hadley explained that despite the fact that Qaeda attacks comprised the "small[est] fraction of the total of incidents...they are responsible for some of most heinous incidents -- the car bombings and other things that result in the massive -- the large civilian casualties, and it is those casualties and those incidents that have provoked the reprisals that the president has talked about."

"It's very important for the American people to understand that there is a key al Qaeda piece in all of this, and that is why one of the principal responsibilities we have, the challenges we have, is to deal with al Qaeda in Iraq," Hadley said.

Hadley added that Qaeda in Iraq was as much as a threat as Shiite death squads.

The survey finding, which includes Americans, Iraqis and third-party nationals hired by companies operating under U.S. government contracts, is significantly higher and wider in scope than the Pentagon's only previous estimate, which said there were 25,000 security contractors in the country.

It is also 10 times the estimated number of contractors that deployed during the Persian Gulf War in 1991, reflecting the Pentagon's growing post-Cold War reliance on contractors for such jobs as providing security, interrogating prisoners, cooking meals, fixing equipment and constructing bases that were once reserved for soldiers.

Official numbers are difficult to find, said Deborah D. Avant, author of the 2005 book "The Market for Force: The Consequences of Privatizing Security," but an estimated 9,200 contractors deployed during the Gulf War, a far shorter conflict without reconstruction projects. "This is the largest deployment of U.S. contractors in a military operation," said Avant, an associate professor at George Washington University.

In addition to about 140,000 U.S. troops, Iraq is now filled with a hodgepodge of contractors. DynCorp International has about 1,500 employees in Iraq, including about 700 helping train the police force. Blackwater USA has more than 1,000 employees in the country, most of them providing private security. Kellogg, Brown and Root, one of the largest contractors in Iraq, said it does not delineate its workforce by country but that it has more than 50,000 employees and subcontractors working in Iraq, Afghanistan and Kuwait. MPRI, a unit of L-3 Communications, has about 500 employees working on 12 contracts, including providing mentors to the Iraqi Defense Ministry for strategic planning, budgeting and establishing its public affairs office. Titan, another L-3 division, has 6,500 linguists in the country.

The Pentagon's latest estimate "further demonstrates the need for Congress to finally engage in responsible, serious and aggressive oversight over the questionable and growing U.S. practice of private military contracting," said Rep. Janice D. Schakowsky (D-Ill.), who has been critical of the military's reliance on contractors.

About 650 contractors have died in Iraq since 2003, according to Labor Department statistics.

Central Command, which conducted the census, said a breakdown by nationality or job description was not immediately available because the project is still in its early stages. "This is the first time we have initiated a census of this robustness," Lt. Col. Julie Wittkoff, chief of the contracting branch at Central Command, said in an interview. Those figures do not include subcontractors, which could substantially grow the figure.

In June, government agencies were asked to provide data about contractors working for them in Iraq, including their nationality, a description of their work and locations where they were working. The information was provided by more than a dozen entities within the Pentagon and a dozen outside agencies, including the departments of State and Interior, Wittkoff said. The count increased about 15 percent from about 87,000 since Central Command began keeping a tally this summer, she said, though the increase may reflect ongoing data collection efforts. The census will be updated quarterly, Wittkoff said.

Three years into the war, the headcount represents one of the Pentagon's most concrete efforts so far toward addressing the complexities and questions raised by the large numbers of civilians who have flooded into Iraq to work. With few industry standards, the military and contractors have sometimes lacked coordination, resulting in friendly fire incidents, according to a Government Accountability Office report last year.

"It takes a great deal of vigilance on the part of the military commander to ensure contractor compliance," said William L. Nash, a retired Army general and a senior fellow at the Council on Foreign Relations. "If you're trying to win hearts and minds and the contractor is driving 90 miles per hour through the streets and running over kids, that's not helping the image of the American army. The Iraqis aren't going to distinguish between a contractor and a soldier."

The census gives military commanders insight into the contractors operating in their region and the type of work they are doing, Wittkoff said. "It helps the combatant commanders have a better idea of . . . food and medical requirements they may need to provide to support the contractors," she said.

Zebari, who arrived here for a foreign ministerial meeting of Iraq's neighboring countries to be held in Cairo later on Tuesday, made the remarks after a meeting with Egyptian President Hosni Mubarak.

According to MENA, Zebari informed Mubarak the outcome of last week's meeting in Jordan between Iraqi Prime Minister Nuri al-Maliki and U.S. President George W. Bush and the latest developments in Iraq as well as efforts exerted to calm down Iraq's situation.

Zebari said situation in Iraq is very difficult given the presence of the international forces and the armed groups, adding Cairo will host within the coming period several meetings by senior Iraqi officials, including President Jalal Talabani and premier Maliki.

On the Iraqi-Syrian relations, Zibari said a new stage has started with the visit of Syrian Foreign Minister Walid al-Muallem to Baghdad and the Iraqi flag will be hoisted on the Iraqi Embassyin Damascus soon and vice versa.

Despite the assassination of the Egyptian ambassador to post-war Iraq Ihab al-Sharif after being kidnapped in July 2005, Iraq hopes Egypt to send another ambassador to Baghdad, said the Iraqi foreign minister.

The witnesses said that opposition demonstrators in downtown Beirut, who were enraged at the site of a coffin being carried through the crowds, ran towards to Sunnis carrying sticks late Monday.

A security source at the scene said that the demonstrators, mostly Shiite members of the Amal Movement to which the late Ahmed Ali Mahmoud, 20, belonged, began wrecking cars and shops in the neighborhood.

Many residents, most of them supporters of late Premier Rafik Hariri and his son Saad Hariri, descended from their homes to fight with the demonstrators and the clashes resulted the injury of 20 people.

The night before, a resident was killed and a number of residents were wounded in the clashes, that coincided with ongoing large protests in downtown Beirut by the opposition camp calling for forming a broader government to include larger representation for the opposition in it.