Officials have confirmed another 20 victims are "seriously injured".
Authorities have detained three men and a woman and defused explosive devices in what appeared to be a carefully planned attack.
One of the men in his late 20s has been charged with murder and is due in court on Saturday.
Luke Western, a Christian and content director of Rhema Media in New Zealand, told Premier he was surprised and saddened by the attack.
"I think New Zealand is a peace-loving nation. I think we've had a long tenure of political stability over the last ten or so years." he said.
"I think that we've welcomed a high number of refugees into New Zealand over the last few years in particular. Immigration's high and our communities really welcome immigrants with open arms.
"Given the fact that this happened at a mosque and there is such freedom in New Zealand - I think that's what's really hurt the psyche - the heartbeat of the country. New Zealanders can't believe this could happen on our own soil."
Authorities have not elaborated on who they detained. But a man (pictured above) who claimed responsibility for the shootings left a 74-page anti-immigrant manifesto in which he explained who he was and his reasoning for his actions. He said he was a 28-year-old white Australian.
Australia's Prime Minister Scott Morrison has confirmed that a man from his country is one of the suspects arrested.
New Zealand Prime Minister Jacinda Ardern called the attack "one of New Zealand's darkest days".
Ms Ardern said the events in Christchurch represented "an extraordinary and unprecedented act of violence" and acknowledged many of those affected may be migrants and refugees.
She added: "It is clear that this can now only be described as a terrorist attack."
None of the suspects were on any watch-lists.
A video, that was apparently live-streamed by the shooter, shows the attack in horrifying detail. The gunman spends more than two minutes inside the Al-Noor mosque firing indiscriminately at men, women and children from close range.
He then walks outside to the street, where he shoots at people on the pavement.
The gunman then walks back into the mosque, where there are at least two dozen people lying on the ground.
After walking back outside and shooting a woman there, he gets back in his car.
There was a second shooting at the Linwood Masjid Mosque that Ms Ardern said killed ten people.
With the chaos in his country Luke Western told Premier that God's peace is needed.
"I think you've just got to pray - as we do, for God's peace," he said.
"Just pray for comfort and for blessing over the families affected, for Christchurch as a city. This is a city that has been embedded in the past, of course with the 2011 earthquakes that struck that city so hard.
"They haven't really recovered from that. It's still being rebuilt in many places of the city.
"This attack now is sort of another blow to an already weakened heart across the city. Pray for Christchurch, pray for New Zealand and pray for God's peace over the situation."
The shooting is the deadliest in the country's history.
Listen to Premier's Eno Adeogun speaking with Luke Western:
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