"We must make sure that former IS [Daesh] militants cannot move freely in our country. Many of them are long being wanted on arrest warrants. Others must be put under constant surveillance once they enter Germany," Barley said.
German Foreign Ministry spokesman Rainer Breul, meanwhile, told reporters that Berlin neither had any contacts with the detained militants nor provided them with consular assistance since its diplomatic mission did not operate in conflict-hit Syria.
READ MORE: Denmark Rejects US Call to Take Back Daesh Fighters, Germany Notes Legal Issues
The issue of the potential return of foreign terrorist fighters to Europe and challenges associated with the returnees has been a pressing issue for several years. The issue was brought up by US President Donald Trump on Saturday, who urged European countries, including the United Kingdom, France and Germany, to take back more than 800 Daesh fighters, captured by the United States in Syria, and put them on trial.
*Daesh [ISIL, IS, Islamic State] — a terrorist group banned in Russia