UNITED STATES government attorneys are relying on emotional appeals as well as material evidence to persuade a jury to convict the four suspects on trial for the 1998 East Africa embassy bombings.

Recent sessions in the five-week-old trial have featured stark testimony from Kenyan and American survivors of the Nairobi attack. Jurors have also been shown graphic images of the aftermath of the blast that killed 214 people and injured more than 4,000 others.

Ambassador Prudence Bushnell, the former US envoy to Kenya, testified on March 1 that she made her way down a blood soaked stairway and past "the charred remains of what was once a human being" as she fled the shattered Co-operative Bank building she was in.

Moments after Ms Bushnell’s wrenching recollection, the prosecution presented Kenya television video footage of the devastation. Jurors gaped and winced as computer screens throughout the cavernous courtroom showed burnt and dismembered corpses in the rubble of Ufundi House and the adjoining US embassy.

A dozen Kenyans, some of them blinded by the blast, took the witness stand in grim succession on March 7 to describe more scenes of horror and agony. One member of the jury wept openly during these accounts, while the 11 others serving on the panel listened and watched, transfixed.

Prosecutors are at the same time assembling a mass of hard evidence intended to link defendants either directly to the twin attacks in Kenya and Tanzania or to the terrorist ring that allegedly planned, financed and executed the bombings.

Last week, attention was on one of the accused, Mohamed Rashed Daoud al-‘Owhali, who is facing a death sentence for his alleged role in the Nairobi blast. Special FBI agent Stephen Gaudin recounted details of the confession al-‘Owhali gave two weeks after the August 7, 1998 attack.

Al-Owhali, 24, a Saudi, is said to have agreed to talk to American agents in Nairobi in return for a pledge that he would be put on trial in the US. "I have a strong preference to have my case tried in a US court because America is my enemy and Kenya is not," al-Owhali allegedly told Mr Gaudin at the time.

In his remarks, as presented to the court by the FBI agent, al-Owhali admitted having travelled to the US embassy as a passenger in the pick-up truck that carried the bomb. The device was constructed, he said, of "TNT, aluminum nitrate, and aluminum powder that were put in, many wooden boxes, wooden crates and these were all connected with wires to batteries in the back of the truck."

On arrival at the embassy, al-Owhali threw a home-made stun grenade supposedly intended to "scatter the Kenyans" guarding the installation. But rather than consummate his planned "martyrdom," al-Owhali chose at the last instant to flee the scene. The driver of the bomb vehicle, a man identified only as Azzam, died in the attack.

The target was selected in part because of the plotters’ assumption that the murder of a female American ambassador would generate especially heavy news coverage. Al-Owhali further stated, according to Agent Gaudin, that the Nairobi embassy was targeted as the base for several US intelligence officials involved in the intervention in Somalia in 1992-93. In addition, the building at the intersection of Moi and Haile Selassie Avenues was believed to afford easy access to a bomb-laden vehicle.

Defence attorneys maintain that al-Owhali’s confession was coerced. Interrogators in Nairobi had threatened to "hang him like a dog," the lawyers argued.

The other three accused men – Wadih el-Hage, 40, an American; Mohamed Sadeek Odeh, 35, a Jordanian; and Tanzanian citizen Khalfan Khamis Mohamed, 27 – have also pleaded not guilty to the charges.

El-Hage, who is facing life imprisonment, acknowledges a longtime close association with Osama bin Laden, but maintains that he was involved solely in legitimate commercial ventures conducted by the wealthy Islamist.

An attorney for Mohamed Odeh admitted in an opening statement at the trial that his client did help transport the bomb that killed 11 people at the US embassy in Dar es Salaam. But the lawyer went on to argue that Mohamed was an almost insignificant underling in the conspiracy who did not deserve to be put to death, as the prosecution had demanded in his case.

Prosecutors have meanwhile played audio recordings and read transcripts of wiretapped telephone conversations involving some of the defendants.