Duesseldorf - Four men accused of membership of an al-Qaeda cell and charged with plotting an attack in Germany went on trial in the western city of Duesseldorf on Wednesday.
Prosecutors said the men, aged between 20 and 30, had intended to stage a "sensational terror attack", but had not decided on a specific target.
A Moroccan named as Abdeladim El-K. was the ring leader, according to prosecutors, and had trained at an al-Qaeda camp in the Waziristan region of Pakistan in 2010.
He learned how to use firearms and make bombs and was ordered to build up a network for organising attacks in Germany.
Under the German legal system, the men will not be asked to formally plead guilty or not guilty, but will have a chance to speak during the trial.
Militant Islamists have cited Germany's military presence in Afghanistan as a grounds for attacking the country.
Abdeladim El-K recruited three men he knew from his student days, a German-Moroccan named as Jamil S., a German-Iranian named as Amid C. and German citizen Halil S, prosecutors said.
He gathered information on the security set-up at public buildings, airports and stations, they added.
Jamil S. worked on producing explosives while Amid C. And Halil S. dealt with communications with the al-Qaeda leadership.
The trial is expected to run until November.