ANKARA, April 27 (Xinhua) -- Turkish Foreign Ministry on Friday summoned a German diplomat over demand for the extradition of former Co-chair of Democratic Union Party (PYD) Salih Muslim.

Turkish officials asked the German Charge D'affaires Robert Dolger to prevent an expected speech to be delivered by Muslim on May 19 in Ludwigshafen, Germany, and extradite him to Turkey, a Foreign Ministry official told Xinhua.

Muslim was arrested on Feb. 25 in Prague following Turkey's request, but then he was freed.

On March 3, Turkish authorities said Muslim was spotted in Berlin, where he also participated in a demonstration organized by Kurdistan Workers' Party (PKK) supporters.

Ankara demanded his extradition from Germany, but Germany has refused the request.

Turkey regards the PYD as the Syrian affiliate of the outlawed PKK, which was listed as a terrorist organization by Turkey, the U.S. and the EU.