The message added that congregations in the capital Wellington had also cancelled services.
Jewish communities in New Zealand and Australia expressed their solidarity with the Muslim community following Friday's attacks on two mosques in Christchurch.
One gunman appeared to have livestreamed the assault that triggered a lockdown in the city.
Prime Minister Jacinda Ardern said it marked “one of New Zealand's darkest days”, adding: “It is clear that this can now only be described as a terrorist attack.”
Three men and a woman have been arrested. At least one was reported to be born in Australia.
Stephen Goodman, the president of The New Zealand Jewish Council told the JC: "The New Zealand Jewish Council has no adequate words to describe how sickened and devastated we are by the coordinated attacks on Christchurch mosques today.
"We offer our full assistance and support to the Muslim community and stand united with it against the scourge of terrorism and racism, which we must do all we can to banish from New Zealand.
We are praying for those all those affected and their families."
The Holocaust Centre of New Zealand issued a statement saying: "We are devastated by the news that our fellow citizens can be attacked in a place of worship and peace.
"Our thoughts and prayers are with the victims, their families and the wider Muslim community.
"We say to all New Zealanders, that acts of hate have no place in our society, and to stand in solidarity against people who believe they do. It is our responsibility to care for, respect and protect everyone and we all have the right to feel as safe in a place of worship as we do in our own homes."
Expressions of solidarity and support were also issued from the Rabbinical Council of Australia and New Zealand, and other leading organisations in Australia.
In Britain, Chief Rabbi Ephraim Mirvis said: "There can be few acts of a greater evil than the massacre of peaceful people at prayer."
He called it "terrorism of the most despicable kind, callously planned and motivated by the scourge of Islamophobia".
The Board of Deputies President Marie van der Zyl said it was a "sickening terrorist attack".
“We are horrified by this sickening terrorist attack against Muslims at mosques in New Zealand. To the victims, the survivors and their families, together with Muslims around the world who have been targets of rising hatred, whipped up by media hostility, we express our absolute and resolute solidarity.”
A spokesperson for Israel's embassy in Wellington said: “Our thoughts and prayers are with the victims of the terror attack in Christchurch. A tragic and sad day for New Zealand. Our hearts go out to all of those affected by this horrible event."
President of The Executive Council of Australian Jewry Anton Block commented: "From the information available to the public, it appears that the murderer or murderers were motivated by white supremacist, neo-Nazi ideology.
“To kill unarmed civilians peacefully gathered at prayer in a place of sanctuary, is an act of utter evil. It is a perverse and cowardly crime that the Jewish community knows only too well."
