- Video report by ITV News Correspondent Juliet Bremner
A man charged with murder over the shootings that killed at least 49 people at two mosques in New Zealand has appeared briefly in court.
Brenton Harrison Tarrant, 28, appeared in court Saturday morning amid strict security and showed no emotion when the judge read him one murder charge.
The judge said "it was reasonable to assume" more such charges would follow.
Two other armed suspects were taken into custody while police tried to determine what role, if any, they played in the cold-blooded attack that stunned New Zealand, a country so peaceful that police officers rarely carry guns.
It was by far the deadliest shooting in modern New Zealand history.
"It is clear that this can now only be described as a terrorist attack," Prime Minister Jacinda Ardern said, noting that many of the victims could be migrants or refugees.
She pronounced it "one of New Zealand's darkest days."
Ms Ardern said the main suspect in the mosque attack legally acquired five guns used in shootings.
In the wake of the attacks the national security threat level in New Zealand has been raised to the second-highest level.
Ms Ardern called Friday “one of New Zealand’s darkest days” and said that the events in Christchurch represented “an extraordinary and unprecedented act of violence”, acknowledging that many of those affected may be migrants and refugees.
- What do we know so far?
The two attacks took place at mosques in Christchurch, the deadliest of which was apparently live-streamed on Facebook from the account of Australian Brenton Tarrant.
The attacks initially began at 1.40pm local time (12.40am GMT).
Forty-one people were killed at Masjid Al Noor in central Christchurch.
Seven people were killed at Linwood Masjid in a suburb of the city, while another person died in hospital.
- What do we know of the suspects?
In a 74-page manifesto posted online and believed to have been written by Tarrant, he describes anti-immigrant motives, saying the victims were a “large group of invaders” who he says “seek to occupy my peoples lands and ethnically replace my own people (sic)”.
He went on to describe himself as an “ordinary white man” who “decided to take a stand to ensure a future for my people".
He said he was not a member of any organisation, but had donated to and interacted with many nationalist groups, though he acted alone and no group ordered the attack.
Days before the attack he posted pictures of magazines for automatic weapons on his website.
Each magazine had names of right-wing terrorists written on them.
None of the suspected attackers were on watch-lists.
Tarrant's former employer, Tracey Gray, told ITV News he "never showed any extremist views or crazy behaviour" when he worked at her fitness facility about seven years ago.
There was strict security at the district court in Christchurch, awaiting a court appearance by the suspect.
More than ten armed officers guarded the courtroom even before the suspect entered.
Police Commissioner Mike Bush said authorities were not aware of other suspects beyond those who were arrested, but added that the authorities could not be certain.
- Who are the victims?
Bangladesh's honorary consul in Auckland, Shafiqur Rahman Bhuiyan, said that "so far" three Bangladeshis were among those killed and four or five others were wounded, including two left in critical condition.
Two Jordanians were among those killed, and others were wounded.
Four Pakistanis were wounded and five are still missing.
Malaysia says two of its citizens were hospitalized, and the Saudi Embassy in Wellington says two Saudis were wounded.
Two Indonesians, a father and son, were also among those shot and wounded.
- What next in New Zealand?
A home in the city of Dunedin, around 225 miles (326km) from Christchurch on the south island, is being searched by police in connection with the attacks.
Neighbouring homes on Somerville Street have been evacuated.
The national security threat level in New Zealand has been raised to the second-highest level.
- How has New Zealand Prime Minister's responded?
Speaking at a news conference on the shootings, Ms Ardern said that while many people affected by the shootings may be migrants or refugees “they have chosen to make New Zealand their home, and it is their home.
"They are us.
"The person who has perpetuated this violence against us is not”.
She promised New Zealand's gun laws "will change".
She said: "Police are working to build a picture of anyone who might be involved and all of their activities prior to this event."
Describing the 28-year-old who has been charged with murder, she said he had not come to the attention of the "intelligence community" nor "the police" for extremism.
Ms Ardern said the suspect had a Category A gun licence which enabled him to legally obtain semi-automatic weapons.
She added: "I am advised that there were five guns used by the primary perpetrator.
"There were two semi-automatic weapons and two shotguns."
When asked by a reporter whether semi-automatic weapons should be banned, she said that it was one issue which should be examined.
She said: "While work has been done as to the chain of events that lead to both the holding of this gun license and the position of these weapons, I can tell you one thing right now, our guns laws will change."
- What did witnesses see?
Shoaib Gani, a worshipper at the Linwood Majid told ITV News how he saw his friends get shot in front of him as crawled to safety and hid behind a table while a gunman massacred others during Friday prayers.
Mr Gani said worshippers continued to pray despite hearing multiple gunshots from outside the mosque, only breaking prayer when people began dropping dead from bullets fired through the window.
"Then I realised that something was happening.
"I dropped to the floor and started to crawl towards the corner," he told ITV News.
"I saw people getting shot.. there was blood everywhere...
"I can't tell you how I felt," he said.
"It was really horrific. I'm traumatised. I can't tell you exactly how I feel right now.
"I'm just happy to be safe and alive."
Witness Len Peneha said he saw a man dressed in black enter Masjid Al Noor and then heard dozens of shots, followed by people running from the mosque in terror.
Mr Peneha, who lives next door to the mosque, said the gunman ran out of the mosque, dropped what appeared to be a semi-automatic weapon in his driveway, and fled.
Mr Peneha said he then went into the mosque to try to help.
“I saw dead people everywhere.
"There were three in the hallway, at the door leading into the mosque, and people inside the mosque,” he said.
“I don’t understand how anyone could do this to these people, to anyone.
He said he helped about five people recover in his home.
Mr Peneha said the gunman was white and was wearing a helmet with some kind of device on top, giving him a military-type appearance.
Mark Nichols told the New Zealand Herald he heard about five gunshots and that a Friday prayer-goer returned fire with a rifle or shotgun.
Mr Nichols said he saw two injured people being carried out on stretchers and that both people appeared to be alive.
Members of the Bangladesh cricket team, currently on tour in New Zealand, narrowly avoided being caught up in the tragedy.
Players and members of the team’s coaching staff were reportedly on their bus, approaching the Masjid Al Noor in Hagley Park, when the shooting started.
Tamim Iqbal tweeted: "Entire team got saved from active shooters!!! Frightening experience and please keep us in your prayers."
His team mate Mushfiqur Rahim added: "Alhamdulillah Allah save us today while shooting in Christchurch in the mosque...we r extremely lucky...never want to see this things happen again.... pray for us".
- What has been Facebook's response?
After it emerged that footage of one of the attacks was streamed online, Facebook said they "quickly removed" the video and deleted the alleged gunman's Facebook and Instagram accounts.
In a statement on Twitter, Mia Garlick from Facebook New Zealand said: "Our hearts go out to the victims, their families and the community affected by the horrendous shootings in New Zealand.
"We're also removing any praise or support for the crime and the shooter or shooters as soon as we’re aware."
Police have urged people not to share the "extremely distressing" and "disturbing" footage, adding that it "should not be in the public domain".
ITV News has taken the decision not to show the distressing footage.
- What has the response been in the UK?
Police patrols around mosques will be "stepped up" in a bid to offer "reassurance" in the UK, the country's counter terror police chief has said.
Security minister Ben Wallace told the House of Commons that later he and the Home Secretary would be speaking with police counter-terrorism leaders and security services "to discuss what further measures we can take to protect our mosques and our communities from any threats here in the United Kingdom".
MPs held a minute's silence in the House of Commons at 11am in memory of those killed.
The Queen has sent a message of condolence to the people of New Zealand, telling them they are in her prayers.
New Zealand is part of the Commonwealth, meaning the Queen is their monarch and head of state.
In her message, the Queen said she was "deeply saddened by the appalling events in Christchurch today.
"Prince Philip and I send our condolences to the families and friends of those who have lost their lives.
"I also pay tribute to the emergency services and volunteers who are providing support to those who have been injured.
"At this tragic time, my thoughts and prayers are with all New Zealanders."
UK Prime Minister Theresa May sent her "deepest condolences" to New Zealand following the "horrifying terrorist attack", adding "my thoughts are with all of those affected by this sickening act of violence".
In a statement she said: "Through terror attacks that have taken place on UK soil we know only too well the pain that such horrifying attacks can cause. As New Zealand has stood by us so we stand shoulder to shoulder with them, and with Muslims in New Zealand, here in the UK and around the world.
"There can be no place in our societies for the vile ideology that drives and incites hatred and fear. Together we will defeat those who seek to destroy our values, our way of life and seek to divide us."
Anas Altikriti, President of the Muslim Association of Britain, said: "Our prayers and thoughts are with the victims and their families during this incredibly difficult time, and to the entire Muslim community in New Zealand."
While the Muslim Council of Britain condemned the "horrific, cowardly and Islamophobic terrorist attacks" and sent their "condolences to the families affected".