For the third year in a row, Al Qaeda released a videotape rallying its supporters near the anniversary of the Sept. 11 attacks, and experts were investigating if the images of the terror network's No. 2 leader were new or not.

In the tape, broadcast Thursday by the Arab television station Al-Jazeera, Ayman al-Zawahri (search) proclaims that the United States will be defeae. An assault weapon was propped against the wall behind him.

"The defeat of America in Iraq and Afghanistan has become a matter of time, with God's help," al-Zawahri said on the tape. "The Americans in both countries are between two fires, if they continue they bleed to death and if they withdraw they lose everything."

After a technical analysis of the video aired on Al-Jazeera on Thursday, the CIA assessed with a high level of confidence that the person who appears is al-Zawahri, an agency official said Friday, speaking on the condition of anonymity.

Experts were also investigating what message the video might be seeking to convey and whether the videotape is actually an older audiotape, now joined with its images.

Pakistani army spokesman Gen. Shaukat Sultan, whose forces staged an offensive against Al Qaeda (search) and Taliban (search) remnants in the border region with Afghanistan this week, said the tape was likely aimed at "boosting the morale of the terrorists who have suffered heavy casualties."

President Bush's national security adviser, Condoleezza Rice, said Friday on NBC's "Today" that the tape was a "reminder that Al Qaeda remains a threat."

Al Qaeda leaders, she said, "are sitting in a cave making these tapes. It's a lot more difficult but they are still a very dangerous organization."

In the latest tape, al-Zawahri makes a rare appearance without Al Qaeda chief Usama bin Laden (search), raising some speculation over bin Laden's fate.

Pakistani Information Minister Sheikh Rashid Ahmed said Friday the Al Qaeda leader might be dead, given his absence. "It isn't clear if Usama is alive or dead," Ahmed told reporters. He later called The AP to clarify his statement, saying, "It is just my political guess that Usama bin Laden is nowhere because we have not heard anything from him for a long time, while statements from Mullah Omar and Ayman al-Zawahri occasionally keep coming," he said.

Secretary of State Colin Powell said in an interview with The Associated Press, "I believe he is still alive, but I can't prove that. He clearly is in hiding and he is on the run."

Powell went on: "He is not popping up on television and he is not showing himself in a way that he can be captured."

Judging from reaction on Web sites known for militant Muslim comment, those who share al-Qaida's view of the United States as the enemy of Islam found reassurance in al-Zawahri's appearance.

"God is great, how beautiful is Sheik Ayman's face," wrote a contributor to one of militant web sites on Friday. "Thank God, who alleviated our worry and pleased the heart."

A previously unknown group calling itself "Supporters of al-Zawahri" posted a Web statement Friday claiming to have kidnapped two Italian aid workers in Iraq, accusing the Italian government of helping U.S. soldiers abuse Iraqi prisoners and saying that if Italy wants to know any more about the women's condition, it must pledge to release all Muslim women held in Iraqi prisons.

The authenticity of the claim could not be verified, but its appearance a day after al-Zawahri's video aired demonstrates how militants try to use current events to draw attention to their cause.

Al-Qaida has issued tapes from bin Laden in the two previous years on Sept. 10. In a videotape released on Sept. 10, 2003, bin Laden and al-Zawahri were shown walking through rocky terrain. In audio tapes with the video, bin Laden praised the "great damage to the enemy" done on Sept. 11.

On Sept. 10, 2002, a video was released showing old footage of bin Laden and an audio message with a voice thought to be bin Laden's naming all 19 Sept. 11 hijackers.

If the latest tape is from al-Zawahri, it would be the first time since December 2001 that bin Laden's No. 2 has appeared in a video in which he is speaking and delivering a message, the official said, although he was purported to have made a statement in an audiotape on June 11.

Al-Zawahri also was shown making a statement on a videotape on April 15, 2002, but Defense Secretary Donald H. Rumsfeld said at the time that the material appeared to be outdated.

In the latest tape, al-Zawahri proclaims that the era of security for Americans is over and they will never enjoy it again unless their government stops what he described as crimes against Muslims in Iraq, Afghanistan and Palestine.

He also warned of plans to tear apart the Arab and Islamic worlds, saying that includes the Arabian Peninsula, Egypt and Sudan, particularly the troubled Darfur region where conflict has raged for 19 months.

Al-Jazeera's presenter said the reference to Darfur, which has drawn recent international attention with criticism of the Sudanese government's handling of the crisis, suggests the tape is new.

Al-Jazeera spokesman Jihad Ballout said his station received the al-Zawahri tape on Thursday, but he refused to say how it was obtained. The station will broadcast less than two minutes of a 12-minute recording, showing "what we deemed newsworthy," Ballout told The Associated Press. Ballout refused to comment on the contents of the unaired portions of the tape, including whether they contained any threats.

Bin Laden and al-Zawahri are believed hiding along the Afghan-Pakistan border.

Al Qaeda carried out the Sept. 11, 2001, attacks on New York and Washington, prompting Washington to move against Afghanistan's Taliban regime, which had sheltered bin Laden. The Taliban were driven from power in late 2001 by a U.S.-led military campaign.