Police Commissioner Mike Bush said that a person was in custody but the police were not sure if there were other suspects.
"As we know (shootings occur) in two locations, a mosque at Deans Avenue, and another mosque at Linwood Avenue," Bush said. "We are not sure if there are other locations outside of that area under threat."
Bush said they were "dealing with a serious and tragic series of events in the Christchurch Canterbury area" and warned people to stay the streets. He asked "anyone who is thinking of going to a mosque anywhere in New Zealand today not to go. To close your doors until you hear us again," he said.
New Zealand's Prime Minister Jacinda Ardern prepared a press conference to shoot at two mosques in Christchurch, which describes it as "one of the darkest days of New Zealand."
"What happened here is an extraordinary and nonsensical act of violence," he said.
Ardern said the attacker had "no place in New Zealand."
"Today is my attitude and I am sure that the attitudes of all New Zealanders are among those who are affected by their families, "he said.
The police said they were in the process of mobilizing every national police source to respond to the incident.
Parts of Christchurch are placed in lockdown while the armed police are designated after receiving shot reports at the city center at 1:40 pm. Friday local time. Mohan Ibn Ibrahim told the witness that he was inside the mosque when the shooting began and he heard the gunman "continuously shoot ten to 15 minutes."
"I was in the mosque. Mosque and there were over 200 people inside The gunmen came behind the gunshots went for a long time We needed to jump on the wall to escape .. I saw many broken glass and bricks behind the mosque, "he said.
"I came to the street where I saw a man taken in his chest," he said, adding that the ambulance and police arrived at the scene.
He said he was a friend to another mosque in the area told him a gunman had opened fire there as well as five people were dead.
"I can not contact my two friends who are in the mosque as well," he said.
A spokesman at Christchurch Hospital told CNN that "many" casualties were sent there, but the number was not confirmed.
The police know a video that is shared online and CNN has not proven that it cares for a gunman walking in an unnamed mosque and opening a fire.
"The second shot, I ran, many people were sitting on the floor," he said. "The gun was at the front door, I ran behind the mosque and I was sitting behind … and I called the police."
According to TVNZ, Nazir saw many deaths and injuries, including three women at
Bush said in a statement that "all schools in Christchurch are placed in lockdown."
"The police urged anyone in the Christchurch center to remain in the streets and report any suspicious behavior at 111," he added.
A video posted on Twitter showed a cricket team of Bangladesh walking away from the mosque. Speaking to CNN, the team's coach said that their bus was taken to the mosque when the shooting took place.
Christchurch is a coastal city of 404,500 residents. It is the second most populous city in New Zealand behind Auckland and Wellington.
In 2010 and 2011, the city suffered a series of devastating earthquakes, with the most destructive of the 6.3 magnitude, killing nearly 200 people and destroying thousands of buildings.
This is a story formation.