The account of Jack Dorsey, Founder and Chief Executive Officer of Twitter, was hacked on Friday, the micro-blogging site announced.
The tweets containing racial slurs and suggestions about a bomb showed up around 20:00 GMT on the @jack account before they were deleted.
Some of the tweets contained the hashtag #ChucklingSquad which was believed to indicate the identity of the hacker group.
The messages contained racial slurs and included a retweet of a message supporting Nazi Germany.
“We’re aware that @jack was compromised and investigating what happened,” a Twitter spokesperson said.
A barrage of comments fired off on the platform questioned why the Twitter co-founder did not secure his account with two-factor authentication, and how disturbing a sign it was that the service was not able to keep its own chief safe on the platform.
“If you can’t protect Jack, you can’t protect… jack,” one Twitter user quipped.
The news comes just as Dorsey and Twitter pledged to clean up offensive and inappropriate content as part of a focus on “safety.”
“This might be the only way to get rid of racist tweets on this platform,” a Twitter user commented.
Cybersecurity researcher, Kevin Beaumont, said the account appeared to have been hijacked “via a third party called Cloudhopper, which Twitter acquired about 10 years ago and had access to his account”.
Cloudhopper enables users to send tweets on their phones via SMS.