It's been two days since New Zealand's "darkest day", as the Prime Minister put it.
Here's everything that's happened so far, from the moment the gunman opened fire to the latest details.
- Christchurch terror attack: Life of alleged killer Brenton Tarrant
- Details emerge of suspect Brenton Tarrant's involvement in rifle club
Planning for the attack
2010 onwards - At some point, alleged gunman Brenton Harrison Tarrant becomes radicalised. He writes of visiting western European nations, and becoming increasingly disgusted at the presence of large immigrant communities.
2017 - Tarrant moves to Dunedin "to plan and train".
Friday: The shooting begins
12:15am - Tarrant exports his manifesto to a PDF document.
1:30pm - He sends Prime Minister Jacinda Ardern a copy of his manifesto just minutes before the attack on Friday began, CNN reports.
The email was sent to a "generic" account handled by staff and Ardern never saw it, chief press secretary Andrew Campbell later said.
The email was reportedly worded as though the massacre had already happened, and it was sent so soon before the attack, there would have been no chance to stop it.
1:40pm - There were reports of shots fired near a mosque in central Christchurch at 1:40pm.
A man told Magic Talk he saw people running out of the mosque, and that he had seen a man in military gear with a high powered gun.
"I heard what I thought was a real loud backfire of a car," the man told Magic Talk.
"And the next minute I turned to my right and just saw people running out of the mosque, and obviously just a couple of more shots and a lady fell over and then a guy in full military gear with what looked like a really high powered gun pointing down the road firing."
Armed police were deployed, and people in central Christchurch were urged to stay indoors and report any suspicious activity.
2:42pm - All schools in Christchurch have been placed into lockdown. Reports of six people dead.
2:47pm - Shootings are now thought to have happened at two separate mosques.
Christchurch goes into lockdown
2:52pm - Christchurch Hospital and Outpatients placed in lock-down. The public are told should not attend Christchurch Hospital unless it's an emergency.
3:12pm - Prime Minister Jacinda Ardern cancels all her afternoon engagements.
3:21pm - Christchurch City Council locks down its central city buildings.
3:33pm - The shooter's car crashes on Strickland St, three kilometres from where the shootings took place. Police cordon off the car due to fears there's a bomb inside.
It's believed the shooter might have been traveling to another target.
4:04pm - Police say one person is in custody, however there may be other offenders.
"We understand that there will be many anxious people but I can assure New Zealanders that Police is doing all it can to resolve this incident," police said in a statement.
"We urge New Zealanders to stay vigilant and report any suspicious behaviour immediately to 111.
"We are mobilising resources nationally and support is being brought into the District."
4:29pm - The Prime Minister's spokesperson says the emergency response system has been activated and all major agencies will meet with the Prime Minister in Parliament's bunker.
5pm - Police say schools are still in lockdown and children are being taken care of by school staff.
"There is no timeframe at this stage for when the lock down will be lifted. Schools will communicate directly with parents when the lockdown is lifted."
5:31pm - Police-Commissioner Mike Bush tells media four people are in custody, including one woman.
5:34pm - Police say the public should not assume the incident is contained to Christchurch and people in other centres should be on alert.
5:56pm - Police say schools across Christchurch are no longer in lockdown.
"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."
Worst gun attack in New Zealand's history
7:26pm - Prime Minister Jacinda Ardern confirms at least 40 people have been killed.
Ten died at Linwood Ave mosque and 30 were killed at Deans Ave mosque.
"It is clear that this can now only be described as a terrorist attack," Ardern said.
"From what we know, it does appear to have been well planned."
Ardern said two explosives attached to suspects' cars have been disarmed.
"One has publicly stated that they were Australian-born. These are people who I would describe as having extremist views that absolutely no place in New Zealand and no place in the world."
Ardern said she could not rule out that there could be more suspects. New Zealand's national security threat level has been lifted from low to high.
7:34pm - Forty-eight patients, including children, are being treated in Christchurch Hospital for gunshot wounds.
Canterbury District Health Board said in a statement the injuries range from minor to critical.
Twelve operating theatres are currently in use with some patients needing multiple surgeries.
9:03pm - Police Commissioner Mike Bush confirms that the death toll has risen to 49, and a man in his late twenties has been charged with murder.
There have been no other threats since the police response to Christchurch.
Three others have been arrested and two had firearms on them. Police are still working to establish their connection to the suspect charged with murder.
10:57pm - Police attend a property on Somerville St, Dunedin in relation to the attack.
"This is a location of interest in relation to the serious firearms incident in Christchurch today," a statement says.
"Evacuations of properties in the immediate area have taken place as a precaution."
Saturday: The aftermath
6am - Nearly half-a-million dollars has been donated to the official Victim Support fund, set up on crowdfunding site Givealittle. More than 7600 people have chipped in to date.
7am - There is shock intelligence agencies did not have any of the four suspects on their watchlists.
"To get something like this underway and to keep it quiet, particularly with the number of people involved, surprises me," former police negotiator Lance Burdett told Newshub.
7:30am - Police say the death toll remains at 49, with two of the 42 injured in a critical condition. One of those is a four-year-old, who is being transferred to Auckland's Starship Hospital.
8:30am - Synagogues across New Zealand are closed this weekend on police advice.
"The Muslim community is at the forefront of our thoughts and prayers," Juliette Moses of the Auckland Jewish community told Newshub.
Suspect appears in court
9am - Armed police are stationed outside the Christchurch District Court ahead of one of the suspects appearing there sometime on Saturday.
10:45am - About 125 extra police officers have been deployed to Christchurch.
Commissioner Mike Bush said a "complex investigation" is underway.
"New Zealand has never seen an event like this before and NZ Police is dedicating all available resources to our response, not only in Christchurch but right across the country," he said.
11:22am - Suspect Brenton Tarrant has appeared in Christchurch District Court, wearing prison clothes and cuffs.
He did not apply for name suppression and has been remanded in custody.
12:55pm - Australian broadcaster Waleed Aly has delivered an emotional speech after the Christchurch terror attacks, saying "this has been coming".
"The most dishonest thing, the most dishonest thing would be to say that I am shocked."
1:15pm - About $2 million has been raised for the victims' families via crowdfunding sites.
More than $1m of that came from New Zealand-based Givealittle, and the rest from LaunchGood.
Hamilton City Council has announced a vigil will be held opposite Hamilton Jamia Masjid Mosque, on Heaphy Tce at 8pm Saturday night.
2:04pm - Vigils are being held across New Zealand today, with one currently underway at Aotea Square in Auckland.
Ministers David Parker and Phil Twyford appear to be in attendance, as is Auckland Mayor Phil Goff.
3:20pm - Attorney-General David Parker reportedly declares that New Zealand will ban semi-automatic rifles.
New information emerges
4:10pm - It has emerged Brenton Tarrant, an alleged shooter, was a member of the Bruce Rifle Club in Milton since 2018.
The vice-president of the club, Scott Williams, said the South Otago club was struggling to come to terms with the events on Friday.
4:55pm - Police are appealing for more information about the Christchurch attacks on Friday.
They have created a "Tell Police" form where people can provide information, photos and other document. Video footage can also be submitted separately.
Families' desperate plight as public grieves
5:30pm - Many families are still desperate to find relatives who may have been caught up in Friday's incident. Hospitals have lists of those who are currently in their care.
8:00pm - A vigil has begun in Claudelands park for people to pay their respects to those affected by the shootings. Vigils are also being held at Takapuna, Tauranga, and in Dunedin.
8:55pm - The Givealittle page set up for those affected by the Christchurch terror attack is now the "fastest and largest" page in the site's 10 year history.
It has raised $2.3 million in 24 hours.
Sunday: Another grim day
5:40am - The alleged killer sent Prime Minister Jacinda Ardern a copy of his manifesto just minutes before the attack on Friday began, CNN reports.
The email was sent to a "generic" account handled by staff and Ardern never saw it, chief press secretary Andrew Campbell said.
6:20am - Cordons remain in place around the mosques at the centre of the tragedy, and part of the city's Southern Motorway remains closed.
Deans Ave, Riccarton Rd, Lindwood Ave and some roads adjacent are not open today.
World reactions flood in
8:15am - Supportive comments and donations have flooded in from across the world for a survivor of the Christchurch terror attack and his four-year-old daughter.
8:35am - Australia has revoked far-right speaker Milo Yiannopoulos' visa after he blamed the Christchurch attack on "extremist leftism and barbaric, alien religious cultures".
Immigration Minister David Coleman - who personally approved the visa just a week ago - said Yiannopoulos' comments were "appalling".
8:50am - In his latest remarks on border security, US President Donald Trump has used language that's been compared to that of Christchurch terror suspect Brendon Tarrant.
Trump issued the first veto of his presidency to override Congress' decision to block his national emergency declaration, intended to free up funds to build a wall on the border with Mexico to stop migrants coming into the US.
"People hate the word 'invasion', but that's what it is," he said.
US news site Vox said that was "chillingly similar" to the content of the alleged Christchurch killer's manifesto, which was published just before the massacre.
Proposed gun crackdown causes divisions
9:15am - Gun fans have been rushing in to buy new weapons, fearing a crackdown, Newsroom reports.
The Christchurch Gun City outlet was reportedly busy just a day after the massacre, and an Auckland shop owner said they've had a significant increase in sales.
Comments left on Facebook page Kiwi Gun Blog showed owners aren't happy with the Government's plan to further restrict ownership.
One post said Prime Minister Jacinda Ardern's comments made her the "salesman of the year", while another said it was "tyranny" to ban semi-automatic weapons of the kind used by the gunman.
Other comments took aim at Ardern's appearance, and another said the "terrorist won".
10:30am - The US media is impressed with Jacinda Ardern's quick focus to crack down on the kinds of weapons used in the Christchurch killings.
"New Zealand shows willingness to curb guns after one, not 1981, mass shootings," a headline from Vox reads, saying there have been 1981 mass shootings in the US since the 2012 Sandy Hook massacre, in which 27 schoolchildren and teachers were gunned down.
US federal gun laws didn't change after that atrocity, with proposals to expand background checks and ban assault weapons voted down in the Senate.
While Ardern has said gun laws here "will change", it remains to be seen just how that might happen.
11:40am - Another person has been taken into custody "due to evidence collected during the investigation", police have announced. That brings the total in custody to four.
But it's still believed Brenton Tarrant was the only one involved in the attack.
"There is no information to suggest this person is linked to the attacks," police said.
"Enquiries are ongoing in relation to this person and we will update you when we are able."
A search of the property in Dunedin where Tarrant is believed to have lived until recently turned up "no items that would present harm to members of the public", but a number of other items of interest were found.
11:45am - The UK's MI5 intelligence agency is reportedly investigating Brenton Tarrant, understanding he may have met with members of far-right groups while in Europe two years ago.
Terror suspect Tarrant's manifesto contained threats against London Mayor Sadiq Khan, and said one of his inspirations was the killer who drove a van into worshippers at a London mosque in 2017.
12:20pm - A former soldier says he tried to warn police about rifle club the alleged Christchurch mosque terrorist trained at.
"The ethos within the club concerned me. It was like being 1980s NRA meeting. It was the perfect breeding place for this kind of thing," Pete Breidahl told Newshub.