The nation's terror alert level was raised to orange in the weeks leading up to the holiday season because of threats that Al Qaeda (search) was possibly looking to use explosives on Air France flights, Fox News has confirmed.

For the first time since the Sept. 11, 2001, terror attacks, a U.S. intelligence source was able to give officials such specific information about how Usama bin Laden's (search) terror group may be planning imminent attacks in the United States using commercial airliners, U.S. officials confirmed to Fox News. The source provided strategic and tactical details of how the terror network wanted to carry out terror attacks on American political and economic targets.

The story was first reported Monday in USA Today.

U.S. counterterrorism and intelligence officials are cryptic about the new source, whose identity is a closely guarded secret. But USA Today reported that the information could have come from high-tech surveillance.

On Dec. 5, U.S. officials received specific information that Al Qaeda planned to use explosives on two Air France flights between Paris and Los Angeles on Christmas Day or New Year's Eve. Air France (search) subsequently canceled six flights during the holidays based on U.S. terrorism concerns. From Dec. 5 to Dec. 19 the new source revealed potential threats to two more Air France flights and an AeroMexico flight, USA Today reported.

The new intelligence source also revealed that Las Vegas was a target on "12/31" and that up to three other international flights could be blown up or hijacked and crashed into buildings. The Department of Homeland Security had concerns that such flights could be flown from London, Paris and Mexico.

"I know we have a lot of sources and technology that is very in depth and very capable of picking up a lot of info most anywhere in the world and sharing that info with people," Rep. Michael "Mac" Collins, R-Ga., and member of the House Select Committee on Homeland Security, told Fox News on Monday.

"I think this is just another example of how much we've advanced in our intelligence community in the past three years."

On Fox News Sunday, Mexican President Vicente Fox (search) said the threats were taken seriously by his government.

"Well, let me put it this way. You cannot take risks when life or death is involved," Fox said. "When you get information that some act of terrorism might happen, or when you get intelligence information that you could face problems, you better act. And that's what we did."

Other threats included bin Laden's desire to launch terror attacks on oil and nuclear facilities.

Two traditionally reliable foreign sources also provided U.S. officials with more general information that Al Qaeda was plotting attacks in Valdez, Alaska; Houston and Galveston, Texas; Tappahannock, Va.; Belgium and Saudi Arabia, officials told USA Today. U.S. authorities concluded that terrorists might be targeting oil pipelines, refineries and nuclear power plants in or near those areas.

The rhetoric on radical jihadist Web sites on the Internet also was escalating, some of it predicting that as many as 100,000 Americans would die in an attack by bin Laden's followers between mid-November and early February.

Those sites also urged Muslims in New York, Washington and Los Angeles to leave town for the holidays.

One counterterrorism official told USA Today that although the Web sites tend to contain more bluster than fact, U.S. intelligence agencies became concerned about the "crescendo about mass casualties" on the Internet.

Many agree that although there were no attacks, raising the terror alert level could have thwarted any imminent danger.

"I believe we might have prevented another possible terror attack," Rep. Eddie Bernice Johnson (search), D-Texas, told Fox News. "I think it might have at least prevented something happening that time and I think it's wise that we continue to be alert because it seems to be a determined efforts to bring pain and suffering" to Americans.

Better Airline Security on the Way

To better boost airline security, U.S. authorities have been testing a computerized system known as CAPPS II (search) to probe the backgrounds of all passengers boarding flights in the United States.

The system would color-code passengers, based on the level of threat they pose before getting on the plane. Those showing up "red" would be detained for questioning" and the information would be used for future legal action, while others showing "green" as posing no threat would be free to board and the information would be wiped from the computer.

The order taking CAPPS II out of the testing phase and into operation could be issued next month, The Washington Post first reported. Foxnews.com confirmed that the government hopes to deploy the system this year.

The General Accounting Office is currently studying the system before it's officially launched.

"If that report shows that the program meets the security and privacy and effectiveness needs as set by Congress, then the program should go forward this year," Peter Kant, vice president of Jefferson Consulting, which represents several of the companies working on CAPPS II.

Meanwhile, French police are still searching for a man believed to have links to Al Qaeda.

Air France said that on Jan. 7, French police were waiting to question a passenger named Abdul Haye, but he didn't show up for the flight from Paris to Los Angeles. The airline said the man was also a no-show for a similar flight on Dec. 24. That flight was canceled due to U.S. concerns over passengers with certain names, including that of "Abdul Haye."

Fox News' Liza Porteus, Anna Stolley and Kelly Wright contributed to this report.