One man in his late 20s has been charged with murders.
The gun Brenton Tarrant used to carry out the attack.
No casualty of Chinese citizen has been reported yet.
New Zealand Police have evacuated homes in Dunedin as they investigate a home "of interest" to the shootings. Dunedin is a city near the southern tip of New Zealand, around 225 miles from Christchurch. He also denied speculation that the hospital had also been attacked.
AFP determined the video was genuine through a digital investigation that included matching screenshots of the mosque taken from the gunman's footage with images available online showing the same areas.
"Multiple fatalities are, as far as we know, at two locations - a mosque at Deans Ave and another mosque at Linwood Ave, Christchurch", Commissioner Mike Bush said in a video statement posted by police on Facebook.
The other two individuals detained are a man and a woman, according to authorities. Jordan's Foreign Ministry confirmed that one Jordanian was killed and five wounded in the attack.
"It doesn't get any more serious", Bush said.
Prime Minister Jacinda Ardern described the shootings as a terrorist attack, adding that it is one of New Zealand's "darkest days".
A spokeswoman for the police said: "Following on from the horrific attacks on mosques in New Zealand we will be conducting reassurance patrols at mosques across the county". New Zealand Mosque Mass Shooting: Bangladesh Cricket Team Unhurt, Tamim Iqbal Tweets About Safety.
People across New Zealand are expressing their condolences to the victims.
Witnesses described the shooter as dressed in a bulletproof vest and a helmet as he opened fire at the Masjid Al Noor mosque at 1:40 p.m. local time, where there could have been as many as 300 people praying.
"We will not let the blood of Muslims go in vain", said one protester. He said he and others escaped by breaking through a glass door.
British Queen Elizabeth II also sent a message to the people of New Zealand on Twitter, and said "I have been deeply saddened by the appalling events in Christchurch today".
Children's screams can be heard in the distance as he returns to his auto to get another rifle.
After walking back outside and shooting a woman there, he gets back in his auto. The video then cuts out.
"What has happened in Christchurch is an extraordinary act of unprecedented violence".
"Who is he to decide who lives and dies?"
Three Bangladeshis were among the dead and one was missing, the consulate said. "It's unbelievably nutty. I don't understand how anyone could do this to these people, to anyone". Flowers, candles and notes have been placed near the mosques where the shooting took place. Of the 49 killed, at least 30 people were killed at Masjid Al-Noor Mosque.
Hospitals said children were among the victims.
Sheikh Mohammed bin Rashid, also Vice President and Ruler of Dubai, said the attacks came on the traditional day of peace for Muslims, as they gathered for Friday prayers.
Traini's lawyer Gianluca Giulianelli said on the radio that his client had repented and "firmly dissociates himself" from the New Zealand killer.
In a statement issued by Áras an Uachtaráin the President said that the attacks have "appalled people all over the world".
In the 74-page manifesto entitled "The Great Replacement", the gunman details his intention to attack Muslims. He also says he is a racist and eco-fascist by nature. "I was a communist, then an anarchist and finally a libertarian before becoming an eco-fascist", he wrote.
Photos of weaponry with distinctive writing on them were posted on the Twitter account on March 13.
The MCB said two mosques in Newcastle and Manchester had been targeted by vandals who spray-painted Nazi swastika symbols in the past two months. Born in Australia to working class, low income family.