Thousands of Germans of all faiths have donned Jewish kippah caps in nationwide rallies to show solidarity in support of the country's Jewish community amid concerns about growing anti-Semitism.

Jewish groups have harnessed public outrage over an attack last week on an Israeli Arab who wore the Jewish cap, or kippah, in Berlin as an experiment.

The young man was subjected to verbal abuse by three people and was lashed with a belt by a Syrian Palestinian.

That attack followed reports of bullying of Jewish children in schools and prompted the head of the Central Council of Jews, Josef Schuster, to advise Jews not to wear kippahs when out alone in big cities.

A man wears a kippah during a demonstration in Berlin. ( Reuters: Fabrizio Bensch )

The Mayor of Berlin, Michael Mueller of the Social Democratic party, urged people to stake a stand:

"And it is sadly the case that these sorts of incidents are starting to pile up and that we keep experiencing it: attacks, bullying, threats and it is even happening at the schools," Mr Mueller said.

"And I thank the Jewish community for organising today's event … anti-semitism has no place in our city," he said.

In Berlin, more than 2,000 people participated in the so-called "kippah march", a police spokesman said.

"It all depends on where I am and with whom I am, but to put it bluntly, there are idiots everywhere," demonstrator Menachem Buschau said.

Similar rallies were held in Cologne and other German cities.

Biggest public stand since before WWII

Jewish community leaders said the demonstrations were the biggest such public display of support since before World War II.

The chairman of the Jewish Community in Berlin, Gideon Joffe, gave his approval to the kippah protests.

"I see support and we feel support from the Muslim side. Together Christians, Jews, Muslims and also atheists, we have to take a stand against this hate together and come up with counter-measures," Mr Joffe said.

"Only then can we carry on living together peacefully in this wonderful city Berlin."

Reuters