SAN FRANCISCO • The account of Twitter chief executive Jack Dorsey was hacked on Friday afternoon, sending public tweets and retweets including racial slurs and curse words to four million followers before Twitter secured the account.

The social media company, co-founded by Mr Dorsey, said the phone number associated with his account was compromised due to a security oversight by the mobile provider.

"This allowed an unauthorised person to compose and send tweets via text message from the phone number. That issue is now resolved," the company said, adding separately there was no indication Twitter's systems had been compromised.

One of the tweets from the hacked account said Nazi leader Adolf Hitler was innocent, while others contained derogatory comments about black people and Jews. There was also a tweet suggesting there was a bomb at Twitter's headquarters.

The account posted a hashtag that was used during the apparent hacking of several YouTube stars last week. The hack underscored potential vulnerabilities in the social media platform, which is widely used by world leaders and politicians.

It comes at a time when social media companies are facing scrutiny over management of their networks, privacy issues and security of user data.

Security researcher Brian Krebs said it appeared that Mr Dorsey was the victim of a SIM swopping attack, in which a mobile provider is tricked into transferring a victim's phone number to a SIM card controlled by someone else.

REUTERS