Ankara, June 16 : Turkey has summoned Jean-Daniel Ruch, the Swiss ambassador to Ankara over a demonstration in Zurich, Switzerland against its President Recep Tayyip Erdogan, in which protesters burned Erdogan's effigy. Turkish Deputy Foreign Minister Mehmet Kemal Bozbay said these acts were unacceptable, calling on Swiss authorities to launch an investigation into the incident and identify those involved as soon as possible, Xinhua news agency reported. Omer Celik, the spokesperson of the ruling Justice and Development Party, concurred with Bozbay's comments by denouncing the demonstration. "We condemn the heinous attack by supporters of the terrorist organization PKK (the outlawed Kurdistan Workers' Party) in Switzerland, which targeted the Turkish flag and our President Erdogan," Celik said on Twitter. The spokesperson also strongly condemned "the connivance of the Swiss authorities to these despicable acts", asking Switzerland to be determined in the fight against terrorism and hate crimes. The PKK, listed as a terrorist organisation by Turkey, the US and the European Union, has been rebelling against the Turkish government for over 30 years. /IANS