The trial, in the northern German town of Celle, got underway amid heightened security on Monday, with the lawyer for one of the suspects, identified as 27-year-old Ayoub B., reading out a statement in which his client's provided his account of the events.

Ayoub B., who like co-accused Ebrahim H.B., stands accused of membership in a terrorist organization, said in his statement that while it was true that he had traveled to "Islamic State" (IS)-held territory last year, he had done so not to fight alongside the militants, but simply to study Islam.

Ayoub B. said that after they arrived in IS territory, he was forced by the militants to undergo weapons training. He added that after it became clear that he would be forced to fight, he quickly began work on a plan to flee the IS and return to Germany.

While Ayoub B. is accused of fighting for IS, Ebrahim H.B. (26) is accused of having volunteered to carry out a suicide attack in Baghdad. According to the prosecution, the attack was scuppered when other members of the group planning it were arrested.

The two are also accused of using the Internet to try to convince further recruits to travel to Syria to fight for IS.

'So that the world knows the truth'

Prior to the start of the trial, Ebrahim H.B. told German public broadcaster NDR that he would use the trial to reveal the inner workings of IS "so that the world knows the truth." He also said that IS recruits were given the option of fighting or carrying out suicide bombings, but that he would prefer being imprisoned in Germany to living in freedom in Syria.

The two men returned to Germany in August and September of last year.

If found guilty, the two suspects, both of whom were born in the northern town of Wolfsburg and hold dual German-Tunisian citizenship, could face up to 10 years in jail.

Editor's note: Deutsche Welle follows the German press code, which stresses the importance of protecting the privacy of suspected criminals or victims and obliges us to refrain from revealing full names in such cases.

pfd/jil (dpa, NDR, AP)