Updated

Prosecutors say they have arrested a German suspected of being a member of the Islamic State group and undergoing weapons training with the extremists.

Federal prosecutors said the 22-year-old, identified only as Kerim Marc B. in line with German privacy rules, was arrested Wednesday at Duesseldorf airport.

He is accused of joining the Islamic State group after traveling to Syria via Turkey in 2013, and then training and fighting with the group before returning to Germany early last year. Prosecutors say he went back to Syria last July.

Authorities estimate that about 600 Islamic extremists have left Germany to fight in Syria or Iraq in recent years, along with many more from other European countries.