British police on Sunday said they are investigating a "racially motivated hate crime" after anti-Semitic graffiti was found daubed across a synagogue and several storefronts in north London.

The Jewish holy symbol had been spray-painted alongside the numbers "9 11" on the premises in the Hampstead and Belsize Park areas of the capital on Saturday night, according to images of the vandalism posted on social media.

AAP

The graffiti appears to reference an anti-Semitic conspiracy theory that Jews were responsible for the 9/11 terror attack in the US.

It was found hours after five people were stabbed at a rabbi's home north of New York in an incident the state governor said was "an act of terrorism", and comes during celebrations for the Jewish festival of Hanukkah.

"This is clearly a concerning incident and one we are taking seriously," said Inspector Kev Hailes of London's Metropolitan Police Service.

"We have liaised with our partners in order to remove the graffiti and various enquiries are underway to find who is responsible," he added in a statement.

"Officers will be on patrol throughout the area in order to provide some reassurance to local communities."

How terrible that Chanukah started with a message of hope and on this last day we face antisemitic graffiti in London and horrific stabbings at a party in New York. We stand with all our communities facing hate.



We send love and solidarity to Jewish communities around the world. — Jeremy Corbyn (@jeremycorbyn) December 29, 2019

Labour leader Jeremy Corbyn, who has been accused of allowing anti-Semitism to flourish within his party, sent a message of "love and solidarity" to Jewish communities in response to the incidents in London and the US.

"How terrible that Chanukah started with a message of hope and on this last day we face anti-Semitic graffiti in London and horrific stabbings at a party in New York," he said on Twitter.

"We stand with all our communities facing hate."