One of Europe's biggest terrorism cases begins this week when the trial opens of a group of Islamists and Spaniards accused of involvement in the Madrid train bombings, which killed 191 people three years ago. The March 11 2004 bombs not only traumatised Spain, but also led to an abrupt change of government and the withdrawal of Spanish troops from Iraq.

29 accused and an army of lawyers and victims will pour into a high-security courtroom on Thursday to hear how the attack was dreamed up, planned, financed and carried out. Twenty Arab men, mostly Moroccans, will face allegations that include providing drugs to pay for explosives, helping suspects escape and preparing the bombs that blew apart four commuter trains like tin cans, injuring almost 2 000 people. Nine Spaniards are charged with supplying and delivering explosives to the Islamist cell.

An Egyptian, Rabei Osman Sayed Ahmed, was sentenced to 10 years' imprisonment by an Italian court last November for his role in the bombings. However, there are 11 major suspects who will not be on trial before the three-judge panel.

Some of the main ideologues and organisers died when seven leading suspects blew themselves up in an apartment weeks after the bombings and three more are still at large.

After the hearings, the judges would take until at least October to consider their verdicts.