Germany’s ambassador to Turkey was summoned by the Foreign Ministry on Monday -- the second time in a week -- according to diplomatic sources.
The sources, speaking on condition of anonymity, did not specify the reason why Martin Erdmann was called.
The summoning had been planned in advance but was carried out on Monday because Erdmann had been outside of Ankara, the sources added.
Monday’s summoning of Erdmann for the second time in such a short period was described as a “coincidence”.
The German diplomat was also summoned on Saturday over a pro-PKK event held in the western German city of Cologne.
At the event, about 3,000 pro-PKK demonstrators gathered at Deutzer Werft Square as part of a so-called international Kurdish festival.
The PKK -- listed as a terrorist organization by Turkey, the U.S. and EU -- resumed its armed campaign against Turkey in July 2015.
Since then, it has been responsible for the deaths of around 1,200 Turkish security personnel and civilians.