A British synagogue and several shops have been covered in antisemitic graffiti during the Jewish festival of Hanukkah.
Police have launched an investigation after the buildings in north London were targeted overnight on Saturday.
The Jewish holy symbol and the numbers “9 11” were spray painted in red and purple on several premises in the Hampstead and Belsize Park area, including South Hampstead Synagogue.
The graffiti references an antisemitic conspiracy theory that Jews were responsible for the 9/11 terror attack.
Police have said they are investigating graffiti as a suspected racially motivated hate crime and have increased security in the communities.
Inspector Kev Hailes said: "This is clearly a concerning incident and one we are taking seriously.
"We have liaised with our partners in order to remove the graffiti and various enquiries are underway to find who is responsible.
"Officers will be on patrol throughout the area in order to provide some reassurance to local communities. Please approach us if you have any questions or concerns.
"I ask anyone who might have seen anything suspicious last night to call us and aid the investigation.
“The Met remains committed to tackling hate crimes in all its forms, and we will continue to work with our partners and the public to do so."
Oliver Cooper, a Conservative councillor for Hampstead, said he had spent Sunday morning patrolling the neighbourhood after “appalled” residents alerted the Community Security Trust (CST), a charity that works to protect the Jewish community.
“My first reaction was shock and horror,” Ms Cooper said. “I’ve had to report antisemitic graffiti in Hampstead a number of times before, including by a banned neo-Nazi group, but I have never seen anything approaching this extent.”
She tweeted: "Sickened by the anti-Semitic graffiti on walls all over Hampstead and Belsize Park this morning. All decent people across Britain stand with our Jewish community - and we must move heaven and earth to eradicate this racist hatred, which was unimaginable just a few years ago."
Responding to the graffiti in London, the Board of Deputies of British Jews wrote on Twitter: “This is a reminder that antisemitism is still with us. Thanks @CST_UK for reporting to @MPSCamden. We hope action is taken to find & punish the perpetrators. Let’s all work to defeat antisemitism in 2020!”
The attack comes after five people were stabbed at a rabbi’s home in New York on Saturday night.