Al-Jazeera had said earlier it would broadcast "video that included scenes showing for the first time Al-Qaeda leaders preparing the September 11 attacks and practicing for their execution."
The video showed Al-Qaeda chief Osama bin Laden and two of the 19 Islamist militants that took part in the attacks, Saudi nationals Hamza el-Ramdi and Wael el-Shemari.
The two bearded men spoke of the situation faced by Muslims in Bosnia and Chechnya.
Fifteen of the 19 attackers on September 11 were Saudis, and Al-Jazeera said it had only aired a few minutes from a document which it said lasted about an hour and a half.
Bin Laden was shown in the company of several dozen men, walking in a deserted, rocky zone that was not identified.
Almost 3,000 people died on September 11, 2001 when suicide hijackers took control of four US passenger planes.
They smashed two of them into the twin towers of the World Trade Center in New York, causing them to collapse.
Another plane slammed into the Pentagon, the US military headquarters building near Washington, and the fourth crashed in a field in Pennsylvania.
The attackers were trained in the martial arts and were armed for the most part with simple box cutters.
Al-Qaeda in Iraq
The footage aired by Al-Jazeera showed hand-to-hand combat practice between people who wore masks over their heads, and one of whom appeared to be training with a knife.
The television station also broadcast a recording attributed to the head of Al-Qaeda in Iraq, Abu Hamza al-Muhajer, in which he said he was sure of victory against US-led forces in the country.
The recording was posted on an Islamist Internet site as well, but its authenticity could not be immediately established.
In the Internet statement, Muhajer urged Sunni Muslims to kill at least one US citizen within the next two weeks.
"Oh followers of (Taliban leader) Mullah Mohammed Omar, oh sons of Osama bin Laden, oh disciples of (slain Al-Qaeda in Iraq leader) Abu Mussab al-Zarqawi ... I urge each of you to kill at least one American within a period not exceeding 15 days," Muhajer said.
The two broadcasts came four days before the fifth anniversary of the September 11 attacks.
Muhajer had already issued a public statement in June, a few days after his predecessor Abu Mussab al-Zarqawi was reportedly killed in a US air strike in Iraq.
In the recording released on Thursday, he said: "I do not doubt for an instant victory" against US-led forces in Iraq, calling President George W. Bush a "liar" and a "dog".
"Do not be proud of the number and the equipment" (of your army), Muhajer said. "The war has just begun."