Anti-Israel graffiti was daubed on a centre used by a messianic Jewish community in response to the Gaza conflict.
“Zionist killers of Palestinian children” and other offensive phrases were painted on the council-run building in Donaghadee, County Down, east of Belfast, where the Shalom Messianic Congregation meets twice a month.
The community was set up in May 2007 and has not previously been the target of an attack.
Congregation leader Jim Clint said: “There are not too many people outside our group who would know we are there. It’s baffled me as to who could have done it, but it’s clearly someone anti-Israeli. It’s very upsetting and to begin with I kept it from many of our older members.”