A man entered a mosque in central Christchurch on Friday afternoon and opened fire on people gathered inside the building.
Shortly afterwards, emergency services responded to the scene and large parts of the city centre placed into lockdown.
This is how the incident has unfolded so far.
FRIDAY 15 MARCH
1.40pm: A man enters a Christchurch city mosque with an automatic weapon and opens fire on people inside the building.
2.11pm: Police confirm they are attending an "evolving situation" in Christchurch after an incident near Hagley Park.
Gunshots are reportedly heard in the area outside the mosque on Deans Ave.
A witness reported hearing at least 20 gunshots and saw what she thought was three people on the ground.
2.17pm: A number of schools go into lockdown in Christchurch as people begin to emerge from the mosque covered in blood.
Police set up cordons in the centre of the city where there are reports of people in the streets who have been shot.
2.54pm: Police Commissioner Mike Bush says the situation is "serious and evolving" and involves an active shooter.
Bush also urges people to stay off the streets in Christchurch and remain indoors.
Shortly afterwards, the Canterbury District Health Board activates its mass casualty plan.
All other buildings on the hospital grounds are put into lockdown and the public asked not go to the hospital unless it is an emergency.
3.20pm: Christchurch Mayor Lianne Dalziel says she is "shocked beyond words" at the events.
"I would never have expected anything like this to happen in Christchurch, I'd never expect this to happen in New Zealand," she says.
4.00pm: Police commissioner Mike Bush confirms one person is in custody but warns the people of Christchurch there may be others who pose a risk to their safety.
Bush also asks for Muslims across New Zealand to stay away from their local mosque.
"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," he says.
The Officials Committee for Domestic and External Security Coordination – commonly referred to as ODESC - begins a meeting at Police National Headquarters in Wellington in response to the shooting.
4.10pm - Prime Minister Jacinda Ardern speaks publicly for the first time in relation to the shooting calling it "One of New Zealand's darkest days." Ardern says many of those in the mosque were likely to be migrants - but they were "us" - New Zealanders. The shooter was not, she says. "This is an extraordinary and unprecedented act of violence."
Ardern says she is flying to Wellington where she will hold emergency meetings with other government officials about the response to the incident.
6.10pm - Lockdown lifted at Christchurch schools.
7.30pm - Jacinda Ardern speaks to media in Wellington and labels the shooting as a "terrorist attack".
She confirms 40 people have lost their lives in the attack. 30 people died at the Deans Ave mosque and 30 at the Linwood Ave mosque. Ardern also said there were more than 20 people seriously injured.
9pm - Police Commissioner Mike Bush said 49 people had lost their lives.
SATURDAY 16 MARCH
8.30am - The gunman, who has been charged with murder, appeared in the Christchurch District Court. He has been remanded in custody without plea until April 5.
9.30am - Ardern said the death toll remains at 49 and work is underway to identify all of those who have died.
She promised gun laws will change after this attack.
1pm - Greg Robertson, chief of surgery at the Canterbury District Health Board, confirms 48 people were admitted to Christchurch Hospital. The hospital is still looking after 39 patients. One child is a 2-year-old and a 4-year-old girl who has been flown to Starship Hospital in Auckland, who is in a critical condition.
Seven people have been discharged from hospital.
SUNDAY 17 MARCH
9.30am - Police commissioner Mike Bush speaks to media and said the death toll has risen to 50. The number of injured has also increased to 50; 36 patients remain in hospital.