Vandals have smashed windows at Christchurch synagogue Beth-El, leaving Jewish community members scared for their safety.
Police are investigating the attack at the Durham Street North property last week, following earlier property damage at the synagogue last month.
New Zealand Jewish Council spokesperson Ben Kepes said he was concerned the vandalism could escalate.
"They started off being verbal on social media, but now have strayed into the realms of vandalism property damage," he said.
"Our concern really as a community is there's been lots and lots of threats straying into physical attacks, and we're concerned that will actually happen."
Police said they received a report of vandalism at a Durham Road North property last week.
"Our enquiries revealed no further lines of enquiry to identify those involved and the matter has been filed," they said in a statement.
"Police are providing reassurance and prevention advice to the community. We will follow up on any further lines of enquiry that may come to light."
Kepes said anti-Semitic slogans had been sprayed on buildings around the country since the outbreak of the Israel-Hamas war, and urged authorities to take the threats against the Jewish community seriously.
"I feel like there is a little bit of an imbalance in terms of response. They are not quite so active when it comes to this particular marginalised group," he said.
Kepes said politicians should tone down the language they used around the conflict.
"It's no surprise that translates into action from people, and that action is addressed against us," he said.