Twitter said Friday the account of chief executive Jack Dorsey had been “compromised” after a series of erratic and offensive messages were posted.

The tweets containing racial slurs and suggestions about a bomb showed up around 2000 GMT on the @jack account of the founder of the short messaging service before being deleted.

Some of the tweets contained the hashtag #ChucklingSquad, which was believed to indicate the identity of the hacker group. The same calling card was left behind during recent hacks of other high-profile social media personalities.

The messages contained racial epithets, and included a retweet of a message supporting Nazi Germany.