Berlin - Video footage showing a 60-year-old German man hurling anti-Semitic abuse at an Israeli restaurant owner in Berlin had been shared 300 000 times on social media on Thursday, with police saying the perpetrator had been detained.

The girlfriend of Yorai Feinberg, the owner of Restaurant Feinberg's in Berlin's Schoeneberg district, shared a video on Facebook that showed the man approaching them outside the restaurant and embarking on a six-minute anti-Semitic rant.

"Why did you stay here after '45," the man, who appears to be ethnically German, says in the video, referring to the end of the Third Reich, during which 6 million Jews were murdered at the hands of the Nazis.

"No one will protect you: You will all land in the gas chambers," he says shortly before a police car is seen arriving at the scene.

Police said in a statement released late Wednesday that they had detained the man, and that he had acted aggressively and verbally abused the police while being handcuffed.

The statement added that the man was now under investigation for hate speech and incitement to violence.

Justice Minister Heiko Maas condemned the man's behaviour on Twitter, describing the incident as "outrageous and inexcusable" and saying that it made clear "that we must all oppose anti-Semitic rabble-rousing in a dedicated and courageous manner."

Facebook apologized that its algorithms had caused the video to be temporarily deleted.

"Our reporting systems are configured to protect people from abuse, hate speech and bullying and we apologize for the fact that occasionally mistakes are made," a Facebook spokeswoman said.

In an interview with dpa on Thursday, Feinberg said the perpetrator's behaviour was "only the tip of the iceberg."

Israeli Ambassador Jeremy Issacharoff visited the restaurant on Thursday and called for a policy of "zero tolerance" towards anti-Semitism.

The debate about anti-Semitism in Germany has flared up in recent weeks as hundreds of Arabs and Palestinians took to the streets to protest US President Donald Trump's recognition of Jerusalem as the capital of Israel.

Some participants in the protests were seen burning Israeli flags and shouting anti-Semitic slurs.

Despite societal concern over anti-Semitic hate crime carried out by Muslims, the vast majority of perpetrators are ethnic Germans, said former Israeli ambassador Shimon Stein and historian Moshe Zimmerman in an editorial published on Thursday in the newspaper FAZ.

Germany saw a slight rise in the amount of anti-Semitic crimes reported in 2017, up to 681 compared to the same period last year, which saw 654, according to the German Federal Ministry of the Interior.