The first video image of Osama bin Laden in nearly two years was broadcast on Al-Jazeera TV on Wednesday, the eve of the second anniversary of the Sept. 11 attacks. The al-Qaida leader was shown walking through rocky terrain with his top aide, both carrying assault rifles.

In an eight-minute audiotape accompanying the video footage, a speaker identified as bin Laden praises the "great damage to the enemy" Sept. 11 and mentions five hijackers by name. On a second tape, a voice said to be that of chief deputy Ayman al-Zawahri threatens more attacks on Americans and calls on Iraqi guerrillas to "bury" US troops.

According to terrorism experts, such tapes reassure al-Qaida sympathizers that the terror network is still a force and its leaders still active and in seeming good health. A tape showing bin Laden would be crucial to that effort and the timing -- a day before the anniversary of the 9/11 attacks, blamed on al-Qaida -- highly symbolic.

Al-Jazeera said the tapes were produced in late April or early May, but the Arab satellite channel did not say how or when it obtained them. The backdrop in the video resembled the border regions between Afghanistan and Pakistan, where US officials believe bin Laden is hiding out.

US intelligence officials will review the tapes to try to determine if they are authentic and when and where they were made, officials in Washington said.

"This is another reminder that they continue to plot to attack us and to attack freedom," Sean McCormack, a spokesman for the National Security Council, said Wednesday.

US President Bush, asked about the tape during a tour of forensics labs at the FBI Academy in Quantico, Va., said he had not heard it yet.

Messages from al-Qaida leaders are sometimes viewed as presaging an attack. Press reports from the Mideast over the last week had suggested a new bin Laden video was set to air Wednesday, one US official said, speaking on the condition of anonymity.

The Department of Homeland Security previously said it did not plan to raise the national terror threat level above its current position at yellow, signifying an elevated threat of attack.

The voice identified as bin Laden praises the Sept. 11 hijackers.

"Those men caused great damage to the enemy and disturbed their plans," the speaker says, calling them true believers who should become an ideal for other believers.

He makes no direct threatening remarks, but the voice said to be al-Zawahri threatens more attacks on Americans.

"What you saw until now are only the first skirmishes," al-Zawahri allegedly says in a 12-minute tape. "The true epic has not begun."

A religious song could be heard in the background of the alleged bin Laden audiotape. Both tapes were translated from the Arabic by The Associated Press.

The video image of bin Laden appeared to be the first since he was shown at a dinner with associates on Nov. 9, 2001 in Afghanistan. That tape was made public a month later.

The tape follows several attributed to other al-Qaida figures who made a point of saying bin Laden was still active in the fight against the West. The last such message, attributed to an al-Qaida spokesman, was aired on the Arab television station Al-Arabiya Sept. 7. In August, an audiotape attributed to al-Zawahri also stressed that bin Laden was alive and well.

Bin Laden was last heard from on April 7, exhorting Muslims in a tape obtained by AP to rise up against Kuwait, Saudi Arabia and other governments he claimed were "agents of America." That audiotape, which CIA analysts said appeared to be authentic, made a vague reference to the Iraq conflict, although it was not specific enough to determine whether it had been recorded before or after the Iraqi war began on March 20.

The videotape broadcast Wednesday shows bin Laden and al-Zawahri dressed in loose-fitting Afghan clothing and flat, rolled brim caps known as pakuls. They walk slowly up and down a rocky hill dotted with green plants.

In one shot, bin Laden, in his late 40s and more than 6 feet tall, is assisted by a walking stick in his right hand and wears a blanket over his left shoulder. He showed signs of age since his last video image two years ago; his beard was whiter.

In several sections of the video, both carry Soviet-made assault rifles.

The two climb to the hilltop and sit resting, looking out over trees and rocky outcroppings, the camera behind them. The video appeared well-planned and well-shot, likely with bin Laden's full cooperation, as he looked over his shoulder at the camera several times.

Neither bin Laden nor his aide spoke on the video, which appeared to be shot during the course of one day. The light in each segment was the same and bin Laden's clothing was the same. He appeared to allow the cameraman time to move ahead to get a series of shots of the al-Qaida leader walking toward the camera. Bin Laden several times looks over his shoulder, giving the impression he is being followed. At one point he waves at the camera.

In one scene a small cluster of wildflowers can be seen, suggesting -- given the apparent high altitude at which the video was shot -- that the videotape was made in early summer. At such an altitude wild flowers would not be blooming in early September.

Al-Jazeera said the film was produced by an Al-Sahhab Co., which it said was "specialized in general in preparing film material for al-Qaida."

In an audiotape, the speaker said to be al-Zawahri refers to US troops in Iraq -- an indication that it was made after American troops entered Iraq last March.

"We salute the mujahedeen brothers in Iraq and press on their hands and ask Allah to bless their sacrifices and valor in fighting the crusaders," the speaker says. "We tell you that Allah is with you and the (Islamic) nation supports you. ... Bury them in the Iraqi graveyard."

The voice attributed to al-Zawahri also refers to the Sept. 11 anniversary.

"On the second anniversary of the raids on New York and Washington we challenge America and its crusade, which is teetering from its wounds in Afghanistan and Iraq," the speaker says. "We tell them that we do not seek to kill, but we will chop off the hand which seeks to inflict harm on us, God willing."

Bin Laden is believed to have been in the border region since December 2001, when US and Afghan troops surrounded a giant cave complex in the eastern Afghan region of Tora Bora. On Dec. 10, troops intercepted a radio transmission that was believed to have come from the al-Qaida leader.

US warplanes blanketed the area with bombs, but the Americans relied largely on local Afghan forces on the ground. Hundreds of al-Qaida suspects are believed to have escaped across the border into Pakistan, and bin Laden may have been among them.

(China Daily September 11, 2003)