Yemeni captive Ali Hamza al Bahlul is on trial at the Guantanamo Bay US naval base in Cuba, where a jury of nine US military officers will have to decide whether creating propaganda is a war crime.

Prosecutors allege Bahlul was Osama bin Laden's media secretary and part of the al Qaeda leader's trusted inner circle. They accused him of scripting the videotaped wills of September 11 hijackers Mohamed Atta and Ziad al Jarrah, who were his roommates in Kandahar, Afghanistan, in 1999.

Bahlul acknowledges in a 2005 letter to another Guantanamo captive that he arranged for the two hijackers to pledge loyalty to bin Laden, typed their wills on a computer and personally delivered them to the al Qaeda leader. He called them "courageous heroes."

Prosecutors introduced into evidence four letters Bahlul wrote to accused September 11 plotters and fellow Guantanamo detainees Ramzi Binalshibh and Khalid Sheikh Mohammed, whom he addressed as "my dear mentor."

In florid language, Bahlul predicts the death of democracy, professes continued loyalty to bin Laden and refers to the US president as "the idiot Bush." He says that if he and his fellow captives are killed, their blood will nurture upcoming generations and Allah will deliver victory over America "and its Jewish hypocrite master."

"So blood, blood, destruction, destruction and let's revenge for the Muslim," he writes in one.

"If I were incapable of jihad with my hands, soul or money, only jihad by word and pen is left," he writes in another.

Journalists were given English translations of the letters, which were written in Arabic and never delivered. Frequently used by al Qaeda itself, counter-terrorism specialists and the media to denote "holy war" against the West, the word jihad signifies for most Muslims a spiritual struggle.

'GROW THE ORGANIZATION'

Bahlul is not accused of direct involvement in any attacks but prosecutors say his work helped make al Qaeda's attacks possible.

He is charged with conspiring with al Qaeda to commit murderous attacks, soliciting to commit murder and providing material support for terrorism. He faces life in prison if convicted.

Bahlul is accused of creating al Qaeda recruiting materials, including a video glorifying the 2000 attack in Yemen that killed 17 US sailors on the warship USS Cole.

The prosecutor, Army Maj. Dan Cowhig, said in his opening statements that the video was shown at weapons training camps in Afghanistan to recruit new al Qaeda operatives and overcome their reluctance to commit suicide attacks by portraying the Cole bombers as martyrs for a righteous cause.

"The primary role of the accused was to grow the organization," Cowhig said.

The video was spliced together from television network images and is part of a longer video Bahlul made about the state of the Islamic world.

His military lawyer, Air Force Maj. David Frakt, is honoring Bahlul's request to present no defence and has been silent in the courtroom. Bahlul was refused permission to act as his own attorney and is refusing to participate in the trial because he does not feel the tribunal is legitimate.

He sat at the defense table in his tan prison jumpsuit, seeming rapt as the prosecutor read from his writings.

Outside the courtroom, Frakt told journalists, "Writing someone's will is not a war crime. If so, there'd be a lot of lawyers on the hook."

Bahlul's is only the second full trial in the Guantanamo court, which has been widely criticized because it allows hearsay evidence and evidence obtained through coercion, including methods many consider torture.