The Prosecutor's office in the German city of Hamburg indicted Mahmut Kaya as a senior figure of the terrorist group PKK which is known for its decades-long campaign of terror in Turkey. He is scheduled to appear before a court in February.

He is accused of running pro-PKK activities in Bremen. The indictment against Kaya says he served as a senior figure for the group's Bremen chapter between 2013 and 2014 and responded to a senior militant in charge of the group's activities in northern Germany who was jailed in another trial in 2015 in Hamburg. Prosecutors say Kaya organized rallies for the PKK in Germany and collected money for the group.

Despite its international status as a terrorist organization, the PKK has enjoyed relative freedom in European cities and has a particularly strong presence in Germany. PKK supporters have been allowed to hold rallies, recruit militants and collect funds in Germany.

According to a 2017 report by the Federal Office for the Protection of the Constitution (BfV), there are 14,500 PKK sympathizers in Germany, with an increase of 500 since 2016. "The PKK continues to be the largest terrorist group in Germany in terms of a number of members and power," the report suggests.