A Jewish seminary has advised its students not to wear skullcaps in public after Rabbi Daniel Alter, 53, was attacked
in front of his young daughter after collecting her from a piano lesson on Tuesday.
A group of four young men hit him in the face repeatedly, shouted religious insults and threatened to kill his daughter. The rabbi needed hospital treatment to his face.
German media reported that the attackers "probably had an Arab background". The country's Central Council of Muslims condemned the attack.
The Abraham Geiger College in Potsdam, currently training 28 rabbis, said it had boosted security around the building as a result of the attack and was checking mail.
"We have also given guidelines to our students on how to behave so that they do not become victims of such attacks," the college's rector Walter Homolka told the Berliner Morgenpost.
"We have advised them not to wear their skullcaps on the street, but to choose something inconspicuous to cover their head with," he said.
He urged the police and intelligence services to deal with violent Muslims. "It would be fatal if we were to see a proxy Middle East
war on German streets," he said.
In an interview with Reuters in 2007, Daniel Alter said he was worried about anti-Semitism
and wore a baseball hat over his skullcap because he was worried about being identified as a Jew.
At the time of the attack, however, his skullcap was not concealed.
Alter was made a rabbi in Dresden in 2006. He and two others were the first to be ordained in Germany since 1942, when the College of Jewish Studies in Berlin was destroyed by the Nazi Gestapo secret police. His father survived Auschwitz concentration camp.
Alter told Bild daily he was shocked at the shameless way his attackers had assaulted him in front of his daughter.
Germany's Central Council of Jews condemned the attack, saying it showed violent anti-Semitism had again become a serious social problem.
Berlin mayor Klaus Wowereit said the incident was "an attack on the peaceful co-existence of all people in the capital".
Germany's official Jewish population has grown more than 10-fold in the last 20 years, largely thanks to an influx of Jews from the former Soviet Union, but anti-Semitic attacks are commonplace and policemen guard synagogues round the clock.
The Central Council of Muslims said Muslims were shocked by such incidents.
"At this time, Jews and Muslims must stand together and make clear: violence of any colour has no place with us," said the Council's chairman Aiman Mazyek in a statement.
The American Jewish Committee called on Germany's parliament to act on a report on anti-Semitism which included recommendations on ways to combat anti-Semitism.
The report also said that anti-Semitism was entrenched in German society, manifesting itself in hate crime as well as in abusive language used by ordinary people.
"German lawmakers should not delay any longer adopting a comprehensive plan to combat anti-Semitism," said Deidre Berger, the AJC's Berlin director.