But hours after the attack copies of the video were still available on Facebook, Twitter and Alphabet Inc's YouTube, as well as Facebook-owned Instagram and WhatsApp. Twitter and Google said they were working to stop the footage being reshared.
Facebook and YouTube did not immediately respond to HuffPost's request for comment on the matter.
Copies of the footage reviewed by Reuters showed that some users had recorded the video playing on their own phones or computers to create a new version with a digital fingerprint different from the original. In another case, the video was shared by a verified Instagram user in Indonesia with more than 1.6 million followers.
Critics have questioned social media giants' ability to police harmful content published to their platforms.
She said the attacks were shown live on Facebook for 17 minutes before being stopped.
"To detect new instances of the video, we are using our artificial intelligence for graphic violence" as well as audio technology and looking for new accounts impersonating the alleged shooter, it said. "Platforms can't prevent that, but much more can be done by platforms to prevent such content from gaining a foothold and spreading". "It is ever clearer that YouTube, in particular, has yet to grapple with the role it has played in facilitating radicalization."Facebook, Twitter and YouTube all said they were taking action to remove the videos".
Earlier previous year, YouTube star Logan Paul posted a clip of a dead body hanging from a tree in Japan, prompting the Google-owned video portal to remove his channels from a preferred advertising programme.
He said the company condemned "the actions of these terrible persons and their disgusting use of our app for these purposes. We will do whatever is humanly possible for it to never happen again".
The major internet platforms have pledged to crack down on sharing of violent images and other inappropriate content through automated systems and human monitoring, but critics say it isn't working.
"All content praising, supporting and representing the attack and the perpetrator (s) should be removed from our platform", Facebook instructed content moderators in India, according to an email seen by Reuters.
Members of a group called "watchpeopledie" on internet discussion board Reddit, for example, discussed how to share the footage even as the website took steps to limit its spread.
Politicians in multiple countries said social media companies need to take ownership of the problem.
Twitter similarly said that they have suspended an account related to the shooting and are working to completely remove the video from the platform.
Experts said the companies could set their detection tools and removal processes to be more aggressive, but YouTube and Facebook have said they want to be careful not to remove sensitive videos that either come from news organizations or have news value.