Ardern said the attack by people with "extremist views" was "unprecedented - unlike any that we have experienced before".
"We also cooperate with law enforcement to facilitate their investigations as required", it said.
New Zealand police indicated that "extremely distressing footage" of the shooting was streamed online as the events took place.
"Many of those who would have been affected by this shooting may be migrants to New Zealand", Ardern said. "Then he walks into the mosque and shoots every single person he can see", Hunt said. A number of IEDS (improved explosive devices) were also found and neutralized by the military.
The Bangladesh cricket team is in Christchurch to play New Zealand in a third cricket test starting on Saturday.
41 people were reportedly killed at the Masjid al Noor Mosque, while seven died at the Linwood Masjid Mosque.
"I'm also anxious about New Zealand because NZ is one of the most peaceful countries in the world, very good reputation so that image can be affected by this kind of activity". It remains unclear if more people were involved.
Meanwhile, New Zealand's health authority reported that at least 48 people are now in hospital in Christchurch being treated for gunshot wounds. "There were three in the hallway, at the door leading into the mosque, and people inside the mosque", Peneha told the Associated Press.
New Zealand media say a shooting has occurred in a second mosque in the city of Christchurch.
Residents of central Christchurch are being cautioned to remain on alert as police continue to investigate the attack.