Interior Minister Thomas de Maizière told the Jewish community in Frankfurt that he was more worried about home-grown Muslim extremists than any arriving among refugees.
He was countered by Salomon Korn, president of the Frankfurt Jewish community, who said that most of the new arrivals came from countries which did not enjoy an "englightened" version of Islam – unlike Turkey, where most Muslims previously living in Germany had their roots.
Korn warned that many of the refugees had grown up in environments rife with anti-Semitism and a belief in Muslims' mission to spread their religion.
But Korn reserved his greatest concern for the native far-right in Germany. Many people who once belonged to the political mainstream were now drifting into the arms of political extremists, he said.
It was a grim message in the week when the Berlin Holocaust Memorial announced that it would receive the five-millionth visitor to its exhibition.
Meanwhile, de Maizière said police statistics showed a small decrease in the number of anti-Semitic crimes in 2015, including violent crimes – "good news", he said.