Mourners pray near the Linwood mosque in Christchurch, New Zealand, on Tuesday. Christchurch was beginning to return to a semblance of normalcy Tuesday as relatives and friends of Friday's shooting victims continued to stream in from around the world. (Vincent Thian/AP)

It took 29 minutes and thousands of views before the live-streamed massacre at a mosque in New Zealand was reported to Facebook and ultimately removed, the social media network said in a new statement late Monday.

The horrific terrorist attack, which killed 50 people at two mosques, played out live on Facebook as the shooter pulled up to one mosque in Christchurch, New Zealand, grabbed guns out of his Subaru’s rear hatch door and stormed inside, opening fire on worshipers. By the time Facebook removed the 17-minute video, it had been viewed roughly 4,000 times, the company said.

Not a single user who encountered the video during the live broadcast reported it during that time, Facebook said. The first user report didn’t come in until 12 minutes after the live broadcast was over — after the footage had already begun proliferating across the Internet.

The new information comes as Facebook and other social media platforms confront a barrage of criticism and calls for boycotts over their role in enabling the viral spread of a graphically violent mass murder peppered with virulent racist commentary. Facebook has said it removed 1.5 million videos of the rampage in the 24 hours following the attack. But critics, including New Zealand Prime Minister Jacinda Ardern, have charged that Facebook and other online platforms have not done enough to develop stronger tools to control the spread of hate speech and violence.

Of the 1.5 million videos Facebook said it removed, more than 1.2 million were blocked automatically upon upload, which Ardern said indicated that Facebook had “powers to take a very direct approach to instances of speech that incites violence or that incites hate.”

She said on Tuesday that the New Zealand government would be looking into the role that social media played in amplifying the terrorist attack.

“There is no question that ideas and language of division have existed for decades,” Ardern said Tuesday from the Parliament floor. “But the form of distribution, the tools of organization — they are new. We cannot simply sit back and accept that these platforms just exist and that what is said on them is not the responsibility of the place where they are published. They are the publisher, not just the postman. This cannot be a case of all profit, no responsibility.”

In the Monday night statement, Chris Sonderby, Facebook’s vice president and deputy general counsel, gave a brief account of how the platform was first alerted to the video and the extent to which it spread before Facebook acted.

The live broadcast of the shooting from the accused gunman, Brenton Harrison Tarrant, was viewed fewer than 200 times, Sonderby said. It would be encountered thousands more times before New Zealand police reported the content to Facebook. Sonderby said Facebook removed the video “within minutes” of receiving the alert from police.

But by then, Sonderby said, a copy of the video had already been posted via a file-sharing site to 8chan, the unmoderated message board where the suspected shooter’s 74-page manifesto raging about the “invasion” of immigrants and sharing false claims of “white genocide” was also shared.

Shot from a chilling first-person vantage point like a violent video game, the video continued to proliferate across YouTube, Twitter and Reddit, as The Washington Post previously reported. Internet users were able to outsmart the platforms’ artificial-intelligence systems intended to detect the banned content simply by making small alterations, such as changing the color or tone of the video. Given the detection problems, Sonderby said Monday that Facebook had “expanded to additional detection systems including the use of audio technology” to aid in automatic removals.

In response to social media’s role in the shooting, some have pledged to boycott Facebook and Google, including advertisers in New Zealand. Burger King, ASB Bank and telecommunications company Spark New Zealand, among others, have all reportedly banded together to pull advertising from the tech giants to make a statement, the New Zealand Herald reported.

In a joint statement Monday, the Association of New Zealand Advertisers and the Commercial Communications Council called on businesses to consider where and how their advertising dollars are being spent and said they would “challenge Facebook and other platform owners to immediately take steps to effectively moderate hate content before another tragedy can be streamed online.”

“The events in Christchurch raise the question, if the site owners can target consumers with advertising in microseconds, why can’t the same technology be applied to prevent this kind of content being streamed live?” the industry organizations said.

Other individual Facebook users have also pledged to boycott the platform. One woman from Tauranga, New Zealand, is leading a 50-hour Facebook blackout in memory of the 50 victims, the New Zealand Herald reported. The blackout will begin at 1:40 p.m. local time Friday, the same time the gunman started broadcasting live on Facebook last week.

A spokeswoman for Facebook declined to answer additional questions from The Washington Post regarding the spread of the video, citing instructions from New Zealand police to limit available details.

“We remain shocked and saddened by this tragedy and are committed to working with leaders in New Zealand, other governments, and across the technology industry to help counter hate speech and the threat of terrorism,” Sonderby said in the statement on Monday. “We continue to work around the clock to prevent this content from appearing on our site, using a combination of technology and people.”

Shibani Mahtani contributed to this report.

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