Khalid Sheikh Mohammed is suspected of organizing the April 11, 2002, bombing in which a truck laden with explosive cooking gas was driven into the ancient Ghriba synagogue on the Tunisian island of Djerba.

The detonation killed 14 Germans, five Tunisians and two French tourists. Thirty others were injured in the blast, for which al-Qaeda claimed responsibility.

Sheikh Mohammed is currently being held in the US detention facility Guantanamo Bay in Cuba on charges of being the mastermind behind the Sept. 11, 2001, attacks on New York and Washington.

Two other men are also facing charges of involvement in the Djerba attack -- a German convert to Islam, Christian Ganczarski, and the brother of the suicide bomber who drove the truck into the synagogue, Walid Naouar.

All three men face a maximum sentence of life imprisonment if found guilty.

Sheikh Mohammed was said to be al-Qaeda's military commander in charge of all foreign operations.

Meetings with Osama bin Laden

Naouar is alleged to have aided the Djerba bomber, his brother Nizar Naouar, by purchasing in France a cell phone from which the latter called Ganczarski and Sheikh Mohammed to organize the attack.

Ganczarski, meanwhile, is alleged to have been an adviser to al-Qaeda leader Osama bin Laden and to have played a key role in the terrorist ring's recruitment drive in Europe.

He is said to have given the go-ahead for the Djerba attack in a phone call placed by Nizar Naouar on the cell phone purchased for him by his brother. He was arrested in France in 2003.

The bomber's uncle, Belgacem Naouar, was sentenced to 20 years imprisonment in Tunisia in June 2006 for helping his nephew construct the bomb -- a large fuel container and detonator -- inside the truck.

The trial is expected to last five weeks. Two other men suspected of involvement in the attacks will stand trial in a separate Paris court hearing in February on minor charges relating to breaking immigration rules and possessing fake documents.

The Ghriba synagogue in the former Jewish village of Hara Seghira has been standing for some 1,900 years. The building survived the attack, though it sustained some fire damage.