One of the men suspected of carrying out a mass shooting in Christchurch published a manifesto that's now being circulated on alt-right forums, where his actions are being celebrated as part of a broader race war.
There are reports of 40 fatalities and at least 20 seriously injured after mass shootings at both Al Noor Mosque in the city's centre and Masjid mosque in the suburb of Linwood.
Police have now arrested four people in connection to the deadly shooting.
One of the gunmen, who identified himself as a 28-year-old Australian named Brenton Tarrant, livestreamed on Facebook the shooting at the Al Noor Mosque.
A Twitter account with the same name also published links to a 17,000-word, 87-page manifesto of white supremacist militant ideology.
The account has been suspended, but the links to the manifesto are still active.
An anonymous user who may have been Brenton Tarrant posted the same links to the manifesto on an 8chan message board hours before the Christchurch shooting, writing: "well lads it's time to stop shitposting and time to make a real effort post".
"It's been a long ride and despite all your rampant fa***try, fecklessness and degeneracy, you are all top blokes and the best bunch of cobbers a man could ask for."
The manifesto, videos and photos have since been circulated on the 8chan, where many are celebrating the shooter's actions.
Investigators will study this information as they seek to understand how a young Australian may have been radicalised through fringe internet forums and conspiracy theories, including ideas of 'white genocide' and United Nations-backed covert population control.
Parallels with Anders Breivik
The manifesto begins with the Dylan Thomas poem 'Do not go gentle into that good night / Rage, rage against the dying of the light', and then describes a situation where 'European countries' including Australia and New Zealand are growing weaker because of their lower birth rates.
The cover page of the manifesto features the 'sonnenrad' - one of a number of ancient European symbols appropriated by the Nazis in their attempt to invent an idealised 'Aryan/Norse' heritage.
The sonnenrad was one of the symbols used at the 2017 Charlottesvile, Virginia, 'Unite the Right' rally.
It also includes references to "white genocide" - probably a reference to the conspiracy theory that was first proposed in the mid-1990s and has since been embraced by the alt-right movement.
It contends that mass migration, racial integration, and low birth rates are being promoted in predominantly white countries in order to weaken them.
The mass shooting also has parallels with that done by Anders Breivik.
On one day in 2011, the Norwegian far-right terrorist perpetrated Norway's biggest massacre since World War 2, killing 77 people. Like the suspected Christchurch shooter, he distributed a manifesto referencing the alleged ongoing genocide against white Europeans.
More recently, white nationalists have referred to attacks on South African farmers as evidence of 'white genocide', and indicative of a global conspiracy.
These ideas were spread through mainstream Australian media, whose newspaper columnists connected the attacks to what they saw as a broader attack on whites across the world.
Dr Joshua Roose, an expert on extremism from the Australian Catholic University, told Hack Friday's mass shooting demonstrates "the very real threat of far-right terrorism attacks in this country".
"There's a history of far-right violence in Australia but not to this extent - not to terrorism," he said.
What this shows is the division between the rhetoric and far-right hate speech and the next step - action and the actual violence that accompanies the violent language - that's the frontier, and that's terrorism.
The author of the Christchurch manifesto claims that, like Breivik, he sought a "blessing in support of the attack" from the Knights Templar, which could refer to any number of modern reincarnations of the medieval Christian order that fought against Muslims in the crusades.
"If that's legitimate it means people were aware of this attack overseas prior to this occurring, which gives this an international dimension," Dr Roose said.
"Right-wing terror attacks have become the most common form of terrorism in the US, by their definition.
"We're seeing the emergence of far right political parties and movements, particularly in Europe, and these groups feed off each other.
"They follow each other on social media and seek to grow and inspire each other as an international movement."
Shooter wrote slogans on guns, ammo
On Tuesday, three days before the attack, the twitter account @BrentonTarrant (which had not yet tweeted) suddenly sparked up, and tweeted 39 times.
The tweets included links to online articles about birth rates among Muslim and non-Muslim populations, including a January 10 Daily Mail article stating that birth rates for white women in the US had fallen relative to that of Hispanic American women.
There are also links to articles about far-right cells within the British and German armies, and about towns in the UK being "shamed" by "Asian gangs".
The account was not active again until Friday, the day of the attack, when it tweeted a single tweet with several links to various file-sharing websites that had the manifesto - apparently to ensure the document would be accessible.
The account also tweeted photos of a bulletproof vest with a sonnenrad logo patch, and a pair of dogtags with the same logos.
Other photos showed ammunition clips on which had been written "Here's your migration compact" - referring to the UN's Global Compact for Migration - and "Vienna 1683" - referring to the Ottoman siege repelled from the walls of Vienna.
It's not clear if these photos were tweeted on Tuesday or Thursday.
8chan users celebrated shooting
On the 8chan internet forum, there have been hundreds of posts explicitly linking the Christchurch mass shooting with Nazi ideology.
8chan is an online forum where users can post with very little moderation. It was set up as an alternative to 4chan, which was perceived as being too highly regulated. It became popular after 4chan banned Gamergate threads - many of which included death threats aimed at female developers.
It's sometimes called 'the world's most vile website'.
Hours after the Christchurch shooting, six of the top seven 'boards' or message rooms on 8chan were about the attack, including one titled 'Brenton Tarrant appreciation station'.
Anonymous users wrote that "finally" one of their own had actually "done something".