Several thousand people turned out to demonstrate against anti-Semitism and racism in Berlin on Sunday as the Israel-Hamas war stirred painful memories of the past in Germany.

Around 3,200 people braved the rain to attend the protest march in the heart of the city, according to a police spokeswoman.

Demonstrators rallied under the slogan "never again is now", a reference to the Holocaust and the crimes committed by the Nazi government.

Anti-Semitism had become "commonplace" in society, Josef Schuster, president of the Central Council of Jews in Germany told the crowd at the protest.

"Sometimes I do not recognize this country," Schuster said.

Germany has registered hundreds of criminal offenses linked to the war in Gaza since the conflict was triggered by Hamas's 7 October attack on Israel.

Among those cases were an increasing number of anti-Semitic incidents, including the targeting of a Berlin synagogue with Molotov cocktails in October.

On Sunday, Berlin police said authorities were investigating an incident in the capital in which a swastika was daubed on the door of a house displaying an Israeli flag.

"If you speak Hebrew on the street, I always turn around to see who is behind me," Nadine Meshulam, an Israeli woman living in Berlin told AFP at the protest.

"Lately you worry more simply about everyday life," Meshulam said.

A pro-Palestinian demonstration was also held in the center of Berlin on Sunday, drawing up to 2,500 people at its peak, according to police. 

Israel on Saturday counted 137 hostages who remain in Gaza, out of around 240 taken on October 7 during attacks that killed about 1,200 people, mostly civilians, according to Israeli officials.

Israel's retaliatory bombardment and ground offensive targeting Hamas has killed at least 17,997 people in Gaza, most of them women and children, according to the latest toll from the Hamas-run territory's health ministry.