The German city of Cologne has refused to allow a major rally in the city on Saturday on the occasion of the opening of the Turkish-Islamic Union for Religious Affairs (DİTİB) Central Mosque by Turkish President Recep Tayyip Erdoğan, citing security concerns, German media outlets reported on Friday

DİTİB did not submit an appropriate security plan, said Cologne Mayor Henriette Reker, and as a result the event could not take place outdoors.

The opening by Erdoğan, who is currently on a state visit to Germany, will now take place in the mosque itself. Only 500 invited guests will be allowed to attend the ceremony.

In the immediate vicinity of the building complex, according to German police, around 5,000 visitors and sightseers could have found a place from which to watch. However, according to DİTİB estimates, it could be expected that up to 25,000 people would congregate at the mosque. Unmanageable crowds should not be permitted without a sufficient plan, said Reker.

A first security plan was received on Thursday by German authorities and fell through because of deficiencies. On Friday DİTİB presented a second, revised plan, but even this did not meet the legal requirements, according to German media.

It previously became public that that a meeting of Erdoğan with North Rhine-Westphalia’s Prime Minister Armin Laschet (CDU) could not take place as originally planned at Schloss Wahn in Cologne. This was decided by the Regional Court of Cologne after the owners of the castle resisted the planned use and applied for an injunction to the court.

Around 3,000 police officers have been tasked with maintaining security during Erdoğan’s visit to Cologne. Thousands of people in the city want to protest the Turkish president’s visit on Saturday, including Alevis and Kurds. A total of at least 10,000 participants are expected at two large demonstrations.