Omer Celik, Turkey's EU affairs minister, tweeted earlier on Sunday that the German constitutional court's decision ran counter to democratic values and free speech.

In a long statement comprising many messages on Twitter, Celik wrote, "The German Constitutional Court's decision on the anti-coup rally in Cologne is an utter backsliding in freedom of speech and democracy. Such a shame to see that EU failed in upholding democracy and showing solidarity with a candidate country in the face of a coup threat."

Turkey's presidential spokesman Ibrahim Kalin released a similar statement, saying, "The practical and legal effort to prevent an event that advocates democracy, freedom and the rule of law and stands against the 15/7 coup attempt is a violation of the freedom of expression and the right to free assembly."

Kalin also said the Turkish authorities were curious to know the real reason why the German court banned the speech's broadcast, adding he hoped that the German authorities would find a satisfactory explanation.

Turkish authorities have launched a massive crackdown ever since a military coup on June 15 failed to overthrow President Recep Tayyip Erdogan. The coup was blamed on Erdogan's former ally and now arch rival, Fethullah Gulen's supporters. Soon after, tensions spilled over to Germany, home to the largest Turkish diaspora.

Around 20,000 pro-Erdogan supporters were attending the rally on Sunday, police said. Several counter-demonstrations were also planned, including one called "Stop Erdogan."

mg/rc (Reuters, AFP)