On Wednesday, authorities in the German city of Cologne announced that they had arrested a 19-year-old Russian national on allegations of training with "Islamic State" (IS) militants in Syria.

Federal prosecutors said the young man, whom they identified only as Suleym K, traveled to Syria via Turkey in late summer 2014 and returned to Turkey a few months later. He was detained on Tuesday and placed in preliminary detention while the government prepares to try him for membership in terrorist organization.

On the same day, a 31-year-old Syrian man was arrested in the rural northern region of Western Pomerania-Greifswald. He is accused of working at an IS checkpoint in Syria and having raped a woman who was trying to flee the conflict. The latter charge would constitute a war crime.

Eleven people were also arrested in Belgium as part of an anti-terrorism investigation, prosecutors said on Wednesday. According to authorities in Brussels, the suspects were detained in connection with an inquiry into the return of former fighters to Belgium.

Investigators stressed that these men were not wanted in connection with major terrorist attacks in Brussels and Parisin 2015 and 2016. But one of the suspects, Khaled Khattab, was friendly with Brussels airport bomber Najim Laachraoui. He also managed to flee Belgium last year in spite of having received a seven-year prison sentence for helping terrorist recruitment networks.

es/mkg (AP, AFP, dpa)