Citing the Turkish military's Operation Olive Branch in Syria's Afrin, a Germany-based left-wing Kurdish youth group has threatened to turn European streets into "rubble and ash," according to Deutsche Welle.
The warning came after pro-Kurdish protesters clashed with police across Germany late last week, which prompted Ankara to urge Berlin to take measures to protect Turkish citizens living in Germany.
Last Friday, German media reported that unidentified assailants set a mosque on fire in the southwestern town of Lauffen am Neckar in Baden-Württemberg.
The arson was followed by a similar incident in Berlin's northern borough of Reinickendorf, where a mosque and a Turkish cultural center were set ablaze on Sunday.
The Turkish Armed Forces launched Operation Olive Branch on January 20. The goal is to clamp down on Kurdish forces in Afrin, an area in northern Syria which is controlled by the US-backed Kurdish YPG forces. The YPG is considered by Ankara to be an affiliate of the Kurdistan Workers' Party (PKK), blacklisted by Turkey as a terrorist organization.