CIA Director George Tenet returned to the Senate Wednesday to warn once more that multiple sources with strong Al Qaeda ties are reporting plots aimed at the United States and the Arabian peninsula.

"[The threat reporting] points to plots timed to occur as early as the end of hajj, which occurs late this week, and it points to plots that could include the use of radiological dispersion devices as well as poisons and chemicals," Tenet told the Senate Armed Services Committee.

"The plots are not idle chatter ... it is the most specific we have seen and is consistent with both our knowledge of Al Qaeda doctrine and our knowledge of the plots of this network, particularly which its senior leadership has been working on for years," he continued.

Tenet said the intelligence community is working in "real time" to disrupt and capture specific individuals. In the meantime, defense officials said Wednesday they have increased air defenses around the nation's capital.

Wednesday was the second day in a row that Tenet warned the Senate — in nearly identical language — of imminent threats from the terror network. The director's appearance was accompanied by a taped message on the Arabic Al-Jazeera satellite television network that appeared to be from Al Qaeda leader Usama bin Laden.

The message urges Iraqis to rise up against the infidel Americans and warned Muslims that any who side with the United States are apostates.

While intelligence analysts are still evaluating the tape both for authenticity and other clues about bin Laden's plans, Tenet said the message could suggest an attack is imminent because his previous messages in October and November were followed by attacks.

"I believe the tape represents an exhortation to his followers. I believe he is trying to raise their confidence and we know from previous tapes that previous tapes occurred roughly prior to previous attacks that have occurred, so the surface is very concerning to us and whether there's any operational signal in this tape or something we can glean at, we'll work on and get back to you on," he said.

The White House has said that the tape, in which bin Laden shows no love for Iraqi leader Saddam Hussein but insists that Muslims have a just cause to support him, is proof that the two are cooperating.

White House Press Secretary Ari Fleischer said that it's troublesome that bin Laden refers to the Iraqi people as muhajadeen brothers, and that people shouldn't take false hope in the fact that the bin Laden and Saddam aren't religious allies.

"The world cannot afford to be in denial," Fleischer said.

Tenet said that solid intelligence from credible, reliable and multiple sources reveal that Iraq is harboring senior members of the Al Qaeda network, and has previously provided training, poison and bomb-making technology.

He added that Iraq continues to procure materials that can be used for weapons of mass destruction, has tested longer-range missiles and is working on unmanned aerial vehicles that can disperse chemical and biological weapons.

On the other side of Capitol Hill, Secretary of State Colin Powell said that getting rid of Saddam will allow a new regime to enter Iraq that will be hostile to bin Laden and refuse his attempts to coordinate terror attacks, perhaps with Saddam's weapons of mass destruction.

Powell also warned the U.N. Security Council to take a strong stand on Iraq or face "irrelevance."

Powell told the House International Relations Committee that he plans to ask the foreign ministers of France and Germany on Friday how much more time weapons inspectors should be given or whether they were only trying to get Iraq 'off the hook.'

Powell said chief U.N. weapons inspector Hans Blix has not asked for more inspectors and that Iraq's failure to comply is the problem.

Powell is expecting inspectors to deliver a critical report by weapons inspectors on Friday. National Security Adviser Condoleezza Rice met with Blix Tuesday to urge him to say that Iraq is not in compliance.

Next week, the United States and Britain are planning to ask for a second resolution for military force. If it is not granted, Powell said the United States will lead a coalition of nations willing to confront Iraq.

"We are reaching a moment of truth with respect to the relevance of the United Nations Security Council to impose its will on a nation like Iraq," Powell said. "We are reaching a moment of truth as to whether or not this matter will be resolved peacefully, or will be resolved by military conflict. The president still hopes it can be resolved peacefully."

Powell said he also has hope that NATO will offer its protection to ally Turkey, which invoked Article 4 of the charter earlier this week that calls for mutual protection: When one ally is threatened, all come to the rescue. So far, France, Germany and Belgium have refused to offer their support to Turkey, suggesting that any cooperation would send a signal of support for war.

That irked House International Relations Committee ranking Democrat Tom Lantos, D-Calif., a Holocaust survivor who said he was "particularly disgusted by the blind intransigence and utter ingratitude" of France, Germany and Belgium.

"If it were not for the heroic efforts of America's military, France, Germany and Belgium today would be Soviet socialist republics," Lantos said. "The failure of these three states to honor their commitments is beneath contempt."

But while Tenet and Powell's information raises considerable concerns among lawmakers, the Bush administration still faced criticism from the Senate Armed Services Committee's lead Democrat, who said that the best way to minimize the chance of war is if the United States works with the United Nations to provide more information to weapons inspectors.

"It's no exaggeration to say the current threats are serious and some of them are imminent," said Sen. Carl Levin, D-Mich., the ranking member of the committee. However, he added he has heard conflicting information that the inspectors have been given all the intelligence they need.

Tenet responded that the CIA and other intelligence agencies have divided sites of interest into three tiers — highest interest, highest value and moderate value — and his team has reviewed everything it has given to various U.N. weapons inspections teams, including the International Atomic Energy Association, U.N. Special Commission and the U.N. Monitoring, Verification and Inspections Commission.

"Of the remaining sites of lower interest on this suspect site list, I had my analysts review all of them last night to see what we had shared ... We identified a handful, one handful of sites which may not have been known to the UNSCOM inspectors, that we will pass to them. We continue to provide additional sites information to UNSCOM either in responses to their questions on a daily basis ... or as we continue to receive new information," he said.

Tenet reminded lawmakers that the burden is on Iraq to disarm, not on weapons inspectors to discover where the weapons of mass destruction are being hidden.

Tenet said raising the national alert level last week, which went up to orange, the second highest threat level, will allow the United States to "buy time" to take security measures to try to prevent terrorists from carrying out an attack at government and business centers.

"The enhanced security that results from a higher level of threat can buy us more time to operate against the individuals are who are plotting to do us harm. And heightened vigilance generates additional information and leads," he said.

The FBI suspects there are "several hundred" Muslim extremists in this country who focus mainly on fund raising, recruitment and training, but the greatest threat to Americans at home are "Al Qaeda cells in the United States that we have not identified."

Some of these cells have probably been in the United States since well before the Sept. 11 attacks, FBI director Robert Mueller said Tuesday.

"The enemies we face are resourceful, merciless and fanatically committed to inflicting massive damage on our homeland, which they regard as a bastion of evil," Mueller said.

The Associated Press contributed to this report.