The Turkish Foreign Ministry summoned Germany's ambassador on Thursday to express the government's disapproval after the southern German town of Gaggenau canceled a referendum campaign event, state media reported.

"Our discomfort and our reaction to these developments have been communicated in person to the German ambassador who was summoned this evening to the (foreign) ministry," a senior Turkish official told news agency AFP on condition of anonymity.

The Turkish Justice Minister Bekir Bozdag had been expected to call on Turkish voters living in Germany to back constitutional reforms that would expand the powers of Turkish President Recep Tayyip Erdogan.

Bozdag called the city's decision "unacceptable" and canceled a planned meeting with German Justice Minister Heiko Maas in Karlsruhe in protest.

"How can we speak of democracy in a country that does not allow one meeting to take place?" the justice minister told Turkish reporters during a visit to France.

Germany's Left Party and the populist, anti-immigrant Alternative for Germany (AfD) praised the Gaggenau decision, urging Berlin to take a stronger stance against Turkish officials campaigning in Germany.

Not enough space

The small, southwestern German town of Gaggenau withdrew permission for the event earlier on Thursday, saying that the hall where the rally was supposed to take place was too small to accommodate the expected crowd.

Due to the fact that the event picked up a great deal of media attention, "the city expects a large number of visitors for which the Bad Rotenfels Hall, the parking lots and the access roads are not enough," the city said in a statement on its website.

The statement also said it did not know whether the event would continue to be held at a different location. The event was to be hosted by the Union of European Turkish Democrats (UETD), a group with close ties to Erdogan's AKP party.

Cologne follows suit

The next minister to travel to Germany as part of the Turkish referendum campaign was supposed to be Economy Minister Nihat Zeybekci, who wanted to address German Turks in Cologne on Sunday.

Following the ban in Gaggenau, Cologne city authorities said they would no longer allow the UETD to use a hall for the rally, a city spokeswoman told news agency DPA, citing security concerns.

Cologne also pulled its permission for an event with Turkish Economy Minister Nihat Zeybekci

"There is no rental agreement for the event on March 5 and there won't be one," the spokeswoman said. She said that the UETD submitted a request last August to rent a large room in the Cologne-Porz city hall for a "theater performance."

After not hearing anything for months about the event, members of the group contacted the city on Wednesday to say the event had changed to an "informational meeting" with a guest speaker who has a "prominent occupation." The city told the group they could not make the room available for the group, saying they could not guarantee the event's safety with such short notice.

Berlin-Ankara ties strained

Of the more than 3 million people of Turkish descent living in Germany, some 1.4 million are eligible to vote in the controversial referendum taking place on April 16. A "yes" vote would expand Erdogan's powers as president, with critics warning that the new presidential system would cement one-man rule in the country.

Relations between Berlin and Ankara have been strained by a series of disputes since the failed military coup that sought to oust Erdogan last July.

Currently, Berlin is demanding the release of Deniz Yucel, a German journalist and correspondent of the newspaper "Die Welt." Yucel was detained in Istanbul over his reports about a hacker attack on the Turkish energy minister's email account.

rs/rg (dpa, AFP, Reuters)