The Star of David has been graffitied on the doors of homes in Berlin, in a chilling echo of antisemitic persecution of Jewish people under the Nazis.
Pictures circulating online show the symbol was drawn on several buildings, with four cases reported to German police in recent days.
Jewish people living in the German capital have reported a rise in abuse following Hamas's bloody attack on Israel last week.
Among those targeted by vandalism was a young Jewish woman, who said she was shocked when she returned to her apartment on Thursday evening to find a star marked on her door.
The woman, who has a mezuzah - a Jewish house blessing - outside her flat, said that the incident was a 'huge shock' and left her 'scared.’
'I speak Hebrew, talk on the phone in Hebrew, and wear a Star of David... I really thought about whether I should stay at home,' the woman told Bild.
Police said they are now investigating 'whether the other houses have a Jewish resident and whether the incidents are connected.'
The incidents amount to a crime under German law, and seem to be an imitation of the persecution of Jews during the 1930s.
During the Holocaust, Nazi brownshirts painted the Star of David in white on the doors of Jewish businesses to discourage non-Jewish Germans from going into them.
It comes as a German intelligence chief claimed that 'some Palestinians are openly and blatantly calling for a kind of Kristallnacht 2.0,' in reference to the Nazis' violent coordinated attacks on Jewish homes and businesses in 1938.
Stephan Kramer, head of domestic intelligence in the state of Thuringia, told Handelsblatt that radicalised sympathisers could 'possibly carry out concrete attacks against Jewish and Israeli institutions and people' amid the Hamas terror on Israel.
Incidents of antisemitism have invoked fear for Jewish people across Europe since the conflict broke out in Israel last Saturday.