A man threw a Molotov cocktail near the Beth Hamedrash synagogue in Golden Greens, in the north west of London, The Daily Mail reported Tuesday.
Police have shut down Golders Green Road and other emergency services are on the scene, the report said.
Officers detained a man over ‘a number of offences’ but said no one has been injured.
“Officers attended and found a man with a vehicle. The man is believed to have set fire to an object before being detained,” a police spokesperson said.
The Community Security Trust, a charity helping the British Jewish community with security, said it was aware of the incident.
It added in a tweet: ‘CST is aware of an ongoing incident in Golders Green that emergency services are attending and appear to have contained.
‘’We are working with police to determine the nature of the incident, which is currently unclear. Please avoid the area whilst the police manage the situation.’’