BERLIN

German police arrested two men with suspected ties to the PKK terror group and seized multiple firearms and a large quantity of illegal drugs, media reported Thursday.

According to Bild daily, the investigation began when police officers in the eastern city of Leipzig stopped a taxi during a routine traffic check on Saturday evening.

The passenger, identified as 23-year-old Numan K., attempted to flee but was apprehended. Officers found five unregistered 9mm pistols with ammunition in his bag.

Authorities then searched an apartment shared by Numan K. and a second suspect, 56-year-old Metin B., where they discovered additional unregistered weapons and more than one kilogram (2.2 pounds) of crystal methamphetamine, according to the report.

Authorities were investigating the suspects' ties to the terrorist group PKK and whether they may have been planning terror attacks, particularly in light of Metin B.'s recent social media posts supporting the PKK and its affiliate, the YPG, in northeastern Syria.

German authorities estimate that the PKK and the YPG have more than 15,000 active followers in the country, many of them pursuing extensive propaganda activities among the Kurdish immigrant population. Germany banned the PKK in 1993. Europol, the EU's law enforcement agency, classifies it as an ethno-nationalist and separatist terrorist organization.