Turkey's Foreign Ministry summons German ambassador
Turkey's President Recep Tayyip Erdogan has blasted Chancellor Angela Merkel, accusing her of using " Nazi measures".
Ties between Turkey, Germany and other European countries have deteriorated in recent weeks amid growing tensions over the April referendum vote and concern over an increasingly authoritarian tone from Ankara.
Authorities in Germany have blocked some Turkish ministers from holding rallies, infuriating Ankara.
"The government is watching this very closely, and we maintain that Nazi comparisons are unacceptable in any form", Demmer said, as quoted by the Hurriyet daily newspaper. They rally together in solidarity.
Turkish officials noted that the protesters had waved banners of a group that is itself illegal in Germany, with the ministry saying that allowing the rally to go ahead was the "worst example of double standards".
Turkish Deputy Prime Minister Numan Kurtulmus on Monday said Turkey was using metaphors about "facism" because it was anxious about European countries forgetting their history and falling into the trap of Nazism once again. "This is why I stated clearly to my Turkish colleague that a boundary has been crossed", stated Sigmar Gabriel in an interview.
Julia Klöckner, the vice-president of Merkel's CDU party, also reacted angrily to the comments. Kloeckner said. She also added that she was urging the European Union to freeze "financial aid amounting to billions of euros" to Turkey.
About 1.5 million Turkish nationals eligible to vote in the referendum live in Germany.
The PKK sympathizers carried banned posters and flags during the rally in Frankfurt and shouted anti- Turkey slogans, even though the Interior Ministry on March 2 updated its list of prohibited PKK symbols to include the image of the terrorist organization's jailed leader Abdullah Ocalan.
Bruno Kahl, head of the BND foreign intelligence agency, claimed Ankara had failed to convince Germany that the cleric, Fethullah Gulen, was responsible for the coup attempt.
Erdogan's spokesman said the remarks were "proof" Berlin was siding with Gulen and his supporters.
Speaking at the International Football Summit at Halic Congress Centrum Istanbul Monday, Erdoğan said: "We may not have been able to bring the Olympics to our country yet, but you also know about the tricks [being played against Turkey] here".
He said Turkey had a proven track record in terms of hosting mega events and preparing the necessary infrastructure for it.
European Commission chief Jean-Claude Juncker warned Sunday that any return of the death penalty in Turkey would be a "red line".