CAIRO — Osama bin Laden urged sympathizers to join the “caravan” of martyrs as he praised one of the September 11, 2001 suicide hijackers in a new video that emerged Tuesday to mark the sixth anniversary of the attacks on the World Trade Center and Pentagon.

A Qaeda traditionally issues a video every year on the anniversary, with the last testament of one of the 19 hijackers involved in the September 11 attacks. This year’s video showed hijacker Waleed al-Shehri, addressing the camera and warning America.: “We shall come at you from your front and back, your right and left.”

The new message came days after the world got its first current look at Mr. bin Laden in nearly three years, with the release of a video Saturday in which the terror leader addressed the American people.

The latest videotape, of the hijacker’s testament, had not yet been posted on extremist web sites. But IntelCenter, a monitoring group in suburban Washington, said it had obtained the 47-minute video and provided it to Associated Press Television News.

It begins with an audiotape introduction by Mr. bin Laden. While his voice is heard, the video shows a still image of him, raising his finger. In the image, Mr. bin Laden has the same dyed-black beard and the same clothes — a white robe and cap and beige cloak — that he had in Saturday’s video.

But it was not known if the audiotape was recently made. In the past, Al Qaeda has used footage and audio of Mr. bin Laden taped long ago for release later.

In the tape, Mr. bin Laden praised al-Shehri, saying he “recognized the truth” that Arab rulers were “vassals” of the West and had “abandoned the balance of (Islamic) revelation.”

“It is true that this young man was little in years, but the faith in his heart was big,” he said.

“So there is a huge difference between the path of the kings, presidents and hypocritical Ulama (Islamic scholars) and the path of these noble young men,” like al-Shehri, Mr. bin Laden said. “The formers’ lot is to spoil and enjoy themselves whereas the latters’ lot is to destroy themselves for Allah’s Word to be Supreme.”

“It remains for us to do our part. So I tell every young man among the youth of Islam: It is your duty to join the caravan (of martyrs) until the sufficiency is complete and the march to aid the High and Omnipotent continues,” he said.

After Mr. bin Laden speaks, the video of al-Shehri appears. Al-Shehri — one of the hijackers on American Airlines Flight 11, which hit the World Trade Center — is seen wearing a white robe and headscarf, with a full black beard, speaking in front of a backdrop with images of the burning World Trade Center.

“We shall come at you from your front and back, your right and left,” al-Shehri said, asserting that America would suffer the same fate as the Soviet Union.

He also praised the losses that America suffered in Somalia in the late 1990s.

“As for our own fortune, it is not in this world,” he said. “And we are not competing with you for this world, because it does not equal in Allah’s eyes the wing of a mosquito.”

Suicide attacks for Al Qaeda and other militant groups often videotape last testaments before carrying out their attacks. Every September 11 anniversary, Al Qaeda has used the tapes in a bid to rally its supporters by glorifying its “martyrs.”

Mr. bin Laden’s new appearances underline the failure to find the terror leader that President Bush vowed in the wake of the September 11 attacks to take “dead or alive.”

On Sunday, Mr. Bush’s homeland security adviser Frances Fragos Townsend sought to play down Mr. bin Laden’s importance — and added a taunt, saying he was “virtually impotent.”

But terrorism experts say Al Qaeda’s core leadership is regrouping in the lawless Pakistan-Afghanistan border region. The latest National Intelligence Estimate says the network is growing in strength, intensifying its efforts to put operatives in the United States and plot new attacks.

Mr. bin Laden’s video on Saturday was his first message in over a year — since a July 1, 2006 audiotape. The images came under close scrutiny from American intelligence agencies, looking for clues to the 50-year-old’s health and whereabouts.