Officers were called to reports that a fire door had been set alight and antisemitic graffiti had been left on a building in Watford.
Hertfordshire Police said it was keen to trace a group of young men in the area at the time. The force believed it was an isolated incident and not linked to arson attacks on the Jewish community in London.
Det Supt Mark Clawson said: “Firstly, I would like to make it clear that we do not tolerate hate crime in our communities in Hertfordshire. I am keen to hear from any witnesses or anyone with information.”
