THE co-founder and chief executive of Twitter has had his own account on the service hacked 

Jack Dorsey's account has been sending tweets and retweets including racial slurs and swearing to four million followers.

Twitter in a tweet said it was aware the account was compromised and was investigating what had happened.

A group referring to itself as the Chuckling Squad said it was behind the breach of Jack Dorsey's account.

One of the tweets claimed Nazi leader Adolf Hitler was innocent, while others contained racist comments against black people and Jews.

There was also a tweet suggesting there was a bomb at Twitter’s headquarters: “Intel is there’s a bomb at Twitter HQ.”

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Twitter said that it was aware that the account had been “compromised” and was investigating what happened. The offending tweets were deleted less than 30 minutes after the initial breach.

“We take threats very seriously,” a spokeswoman for Twitter said in response to a question about the bomb threat. “We have looked into this threat and can confirm it is not credible.”

The account tweeted out a flurry of highly offensive and racist remarks for about 15 minutes.

The messages - some posted directly by the @jack account, and others retweeted from other accounts - used the n-word and made anti-Semitic comments referencing the Holocaust.

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Shortly after the hack, the offensive tweets and retweets were deleted. Certain Twitter accounts named in the compromised tweets and retweets appeared suspended on Friday.

A chat channel on Discord, a separate website, was apparently set up by the group to discuss and joke about the attack - but was quickly shut down.

The Chuckling Squad has taken credit for a number of attacks on high-profile Twitter accounts recently, including @Etika, an account belonging to YouTube personality Desmond Amofah, who died earlier this year in an apparent suicide.