The Arabic television channel Al Jazeera has aired a new videotape of a man it says was one of the September 11 hijackers, reading his will and saying it was a Muslim duty to fight the "American enemy".
"America is the enemy that every Muslim should fight. There is no way the Arab nation can be saved except through jihad (holy war)," said the speaker, identified as Saeed Alghamdi, wearing military fatigues and an Arab headscarf.
The tape aired today also showed Alghamdi during military exercises in a remote area which Al Jazeera said was in Afghanistan.
He was shown jumping out of a truck and opening fire with an automatic rifle.
Alghamdi was among those who seized control of United Airlines flight 93, which crashed in a field in Pennsylvania after an apparent struggle on board. He had several aliases and may have been Saudi Arabian, but his exact background remains unclear.
The tape came two days after al Qaeda leaders Osama bin Laden and Ayman al-Zawahri issued audio- and videotapes marking the September 11, 2001 attacks on U.S. cities.
The speaker promised more attacks by Muslim fighters against the United States.
"I tell you our battle with you will continue... We will erase the shame (inflicted on Arabs) with our hands and all our force."