Turkish President Recep Tayyip Erdogan likened Germany's cancellation of public appearances by two of his ministers to Nazi practices, aggravating frictions that had already flared over Turkey's human rights record.
Germany's decision has "nothing to do with democracy," Erdogan said at an event in Istanbul, state news agency Anadolu reported.
"Recent practices are no different from the Nazi ones of the past."
The German Government press office didn't immediately respond to calls seeking comment, but Merkel's Christian Democratic Union deputy parliamentary leader Michael Fuchs called Erdogan's Nazi references "outrageous".
"The Nazi comparison, the slur on German democracy is as far removed from reality as it gets but we shouldn't be provoked," Fuchs said, adding that the German Government will move on and ignore the comments to de-escalate tensions.