4:19 a.m.: Police commissioner Mike Bush said the death toll has increased to 49 people, with 41 people being killed at one mosque and seven at the other. An additional person died at the hospital.
A man in his late 20s has been charged with murder. One of the people in custody was apprehended at the scene with a firearm, but Bush said that person "may have had nothing to do with this incident." Officials are still working out the involvement of the other two people in custody.
New Zealand's law enforcement agencies had no prior information about any of the suspects, Bush said.
The commissioner said police were not actively looking for any other suspects.
He said it would "not be proper" to comment on how one suspect could have carried out the two shootings, but added: "This was a very well-planned event."
It had been reported earlier that two vehicles were found with IEDs attached, but Bush corrected that one vehicle had been discovered with two IEDs.
3:49 a.m.: Parents of a 35-year-old son was worshiping at the mosque on Friday afternoon told TV 3 New Zealand they had not heard from him. "I don't know if he's still alive or dead ... we've been waiting and waiting and no news, so we came here to see if he's inside the mosque dead. I just want to know any news about him," the mother said.
The parents said they moved from Iraq to Christchurch 22 years ago to come to a safer country. They said he goes to the mosque every Friday.
2:51 a.m.: Forty-eight people, ranging from young children to adults, are being treated for gunshot wounds at Christchurch Hospital, according to David Meates, Chief Executive, Canterbury District Health Board. Around 200 family members are on site awaiting news of their family members.
"Once we have provided for the medical needs of those injured, and the wellbeing of their families and whanau, we will be able to focus on the psychosocial wellbeing of our wider Canterbury community," Meates said in a statement.
2:36 a.m.: There are 40 people who were killed in the two mosque shootings, Prime Minister Jacinda Ardern said at a press conference. Dozens more are being treated for injuries at local hospitals.
"It is clear that it can only be described as a terrorist attack," Ardern said.
The national security threat level increased from low to high, but both domestic and international flights will continue out of the country's airports, except for Christchurch.
Ardern said there are four people in custody, three related to the shooting. She said those three are comprised of one suspected shooter and two "associates."
She said the suspects have "what I would call extremist views -- they have no place in New Zealand or in the world."
Ardern said she wanted to send a message to the suspects: "You may have chosen us but we utterly reject and condemn you."
1:31 a.m.: In the manifesto, the gunman rhetorically asked himself why he chose to use firearms, or guns, to carry out the attack. He answered that "I chose firearms for the affect it would have on social discourse," adding that "with enough pressure the left wing within the united states will seek to abolish the second amendment, and the right wing within the U.S. will see this as an attack on their very freedom and liberty."
"The U.S. into many factions by its Second Amendment, along state, social, cultural, and most importantly, racial lines," he said.
1:16 a.m.: In a manifesto that appears to have been posted around the time of the attack, a man who claimed responsibility for the shootings describes himself as an "ordinary" 28-year-old born in Australia. CBS News cannot confirm that it was actually posted by the attacker.
He says his parents are of Scottish, Irish and English descent and writes about what he calls "white genocide" driven by a "crisis of mass immigration."
He says he carried out the attack "to show invaders that our lands will never be their lands...as long as the white man still lives." He says "we must ensure the existence of our people, and future for white children."
The purported shooter says he is a supporter of Donald Trump's in one sense, but not completely: "As a symbol of renewed white identity and common purpose? Sure. As a policy maker and leader? Dear god no."
1:45 a.m.: Law enforcement officials in the two largest cities in the United States have announced they are increasing security forces at mosques.
One of the suspects in New Zealand appears to have deliberately targeted Muslims in mosques during Friday prayers. The NYPD released a statement to the public saying they are "closely monitoring events in New Zealand, and out of an abundance of caution is assessing security at locations around the city."
The LAPD said in a Twitter post they are "providing extra patrols around mosques."
1:26 a.m.: Police have ended the lockdown on schools, allowing worried parents to pick up their children. The two mosques are still under lockdown as is the hospital where the victims were taken.
"We would like to reassure members of the public that there is a large police presence in the city and the safety of the community is our priority," police said in a statement.
12:42 a.m.: Police commissioner Mike Bush said at a press conference that there are four people in custody. He said three are men and the other is a woman.
"I won't assume there aren't others," Bush said.
He did not give an exact number of people killed or injured but said there were a "significant" number of fatalities.
He said they "aren't assuming" it is limited to Christchurch.
There were a number IEDs attached to vehicles that were stopped, Bush said.
Police officers will now be carrying weapons.
12:23 a.m.: Police said there multiple casualties at two mosques.
Police also urged all mosques in New Zealand close their doors and asked residents to refrain from visiting.
Residents of Christchurch were also asked to stay indoors.
11:55 p.m.: Prime Minister Jacinda Ardern said in a news conference that "it's clear this is one of New Zealand's darkest days."
"Clearly what has happened here is an extraordinary and unprecedented act of violence," Ardern said.
Ardern said many of the people directly affected by the shooting may be migrants or refugees. "They have chosen to make New Zealand their home and they are us ... there is no place in New Zealand for acts of unprecedented and extreme violence, which it is clear this is."
11:55 p.m.: Witness Len Peneha told the Associated Press he saw a man dressed in black enter the Masjid Al Noor mosque and then heard dozens of shots, followed by people running from the mosque in terror.
"I saw dead people everywhere," Peneha said. "There were three in the hallway, at the door leading into the mosque, and people inside the mosque. It's unbelievable nutty. I don't understand how anyone could do this to these people, to anyone. It's ridiculous."