CHRISTCHURCH - New Zealand police warned against sharing footage relating to a deadly shooting in Christchurch on Friday (March 15), after a video online showed a gunman filming himself firing at worshippers inside a mosque.

“Police are aware there is extremely distressing footage relating to the incident in Christchurch circulating online,” New Zealand police said in a Twitter post. “We would strongly urge that the link not be shared. We are working to have any footage removed.”

The shooter identified himself as "Brenton Tarrant" - a white, 28-year-old Australia-born man, NZ Herald reported.

The livestream began as the gunman drove to Al Noor Mosque in Deans Avenue, parking his car in a nearby driveway. According to NZ Herald, the beige station wagon contained a cache of weapons and ammunition in the front passenger seat and boot, along with petrol cannisters.

He then armed himself and walked into the mosque. Once inside, he began shooting indiscriminately.

He then exited the mosque through the front door - after just under three minutes inside, and headed into the street - firing random shots as cars drove past.

He returned to the beige Subaru station wagon parked in a nearby driveway to get more ammunition from the boot.

He fired more shots on the street at no apparent target, and said: "Looks like we won't get the bird today boys."

Police are aware there is extremely distressing footage relating to the incident in Christchurch circulating online. We would strongly urge that the link not be shared. We are working to have any footage removed. — New Zealand Police (@nzpolice) March 15, 2019

He then re-entered the mosque to check for survivors. The 17-minute video ended as the gunman drove away from the scene at speed.

Agence France-Presse confirmed the video was genuine through a digital investigation that included matching screenshots of the mosque taken from the gunman’s footage with multiple images available online showing the same areas.

This included the entrance of the mosque, which has a number of distinct features such as a fence, postbox and doorway.

Inside the mosque, the gunman’s footage showed distinctively patterned green carpet that also matched images tagged on Google Maps as being at the same location.

Distinctive writing on the gunman’s weapons seen in the footage also matched images posted on a Twitter account using the same name and cartoon profile picture as the Facebook Live video.

In a lengthy manifesto published online the supposed shooter outlined who he was and why he carried out the massacre at the Christchurch mosque, NZ Herald reported.

The Facebook account that posted the video was no longer available shortly after the shooting. The Twitter account of the same name was quickly suspended.