By Maria Sheahan and Ece Toksabay
BERLIN/ANKARA (Reuters) - Turkey's foreign minister accused Germany on Wednesday of hostility towards his country and Islam, and Berlin complained of increased Turkish espionage on German soil as acrimony between the two NATO allies showed no sign of abating.
Ankara is furious over the cancellation of several rallies by Turkish ministers in Germany, while Berlin has demanded the immediate release of a Turkish-German journalist detained on terrorism charges.
Turkish ministers want to rally support among Germany's large ethnic Turkish community for President Tayyip Erdogan's bid to increase his powers in a referendum on April 16. Germany has said they can do so, provided they respect local laws, but has canceled several rallies, citing security concerns.
Foreign Minister Mevlut Cavusoglu was allowed to speak at a rally in Hamburg on Tuesday evening, but he remained very critical of Berlin's stance after talks in Berlin on Wednesday with his German counterpart Sigmar Gabriel.
"In Germany we see many politicians and the press ... are very harsh and very anti-Turkey and we even see Islamophobic sentiment," Cavusoglu told reporters.
"This is what we see as unacceptable," he said, urging media to stop their "black propaganda" against Turkey.
Cavusoglu said Turkey wanted to remain friends with Germany but that it was for Berlin to decide and to act accordingly.
Speaking at a separate event after meeting Cavusoglu, Gabriel tried to strike a conciliatory note, mindful that Germany needs Turkey's active cooperation in helping to slow the flow of migrants and refugees to Europe.
"Whatever differences and arguments we have, there is no alternative to talks because (only) then is there a possibility of returning, step-by step, to normalized and friendly relations between Germany and Turkey," said Gabriel.
But he also made clear that campaigning in Germany came with certain conditions, including respect for the "ground rules", and said comparisons with Nazi Germany overstepped the mark.
Gabriel was referring to comments by Erdogan on Sunday in which he described the cancellation of some political rallies in Germany as "fascist actions" reminiscent of the Nazi era.
Bilateral relations have soured significantly since last July's failed coup in Turkey, with Germany and other European countries criticizing the scale of Erdogan's crackdown on suspected supporters of the coup.
The arrest of the journalist Deniz Yucel has further strained ties in recent weeks.
The editor-in-chief of newspaper Die Welt, Yucel's employer, wrote an open full-page letter to Erdogan on Wednesday saying the current state of bilateral relations did not reflect what the two nations had in common.
"You can change that. You of all people. Releasing Deniz Yucel would send a signal," Ulf Porschardt wrote in the letter, printed in both German and Turkish in the newspaper.
Also on Wednesday, the German domestic intelligence agency BfV expressed concern about increased Turkish espionage in Germany and said internal Turkish divisions over Erdogan's referendum were playing out among ethnic Turks based in Germany.
BfV chief Hans-Georg Maassen warned of "proxy fights" between supporters of the militant Kurdistan Workers Party (PKK) and right-wing Turkish nationalists on German streets.
(Additional reporting by Andrea Shalal, Michelle Martin, and Reuters TV and Ankara and Istanbul bureaus; Writing by Madeline Chambers; Editing by Gareth Jones)