"There is no place in New Zealand for such acts of extreme and unprecedented violence, which it is clear this act was", Ardern said.
Police have taken four people into custody - three men and one woman.
NY police ups security after Mosque shootings. There were also "possibly" two improvised explosive devices on one vehicle, Bush said.
The attacker is believed to have livestreamed at least one of the attacks.
"There was a lady screaming "help, help" and he shot her point blank in the face", he said.
YouTube's handling of the footage drew criticism from British Labour Party Deputy Leader Tom Watson, who argued that if the site can't halt the dissemination of the videos, it should suspend new uploads across the board.
Facebook said it had removed the shooter's Facebook and Instagram accounts and deleted the video.
AFP has examined the footage, which has subsequently been taken down.
Alberta won't follow Ontario's ban — Cellphones in class
During this consultation we heard that 97% of respondents support some form of a ban on cellphones. The improvements were largely seen among the students who were normally the lowest achieving.
She said earlier Friday that migrants and refugees appeared to be most affected by the shootings.
"We urge New Zealanders to stay vigilant and report any suspicious behaviour immediately to 111".
A social media account had also posted a number of pictures of a semi-automatic weapon covered in the names of historical figures, many of whom were involved in the killing of Muslims.
The multiple fatalities were at two locations: a mosque at Deans Ave and one at Linwood Ave.
"Police are responding with its full capability to manage the situation, but the risk environment remains extremely high". Reuters was unable to confirm the authenticity of the footage.
He said the mosques in Christchurch and Linwood would be the targets, as would a third mosque in the town of Ashburton if he could make it there, as per reports by PTI.
The gunman, described as a white man in his 20s, also attacked the Al Noor Mosque in Christchurch during prayers on Friday.
"Just around the entrance door there were elderly people sitting there praying and he just started shooting at them".
A neighbor described mass casualties inside the mosque and said he saw the gunman flee.
"There were bodies all over", he said.