Twitter CEO Jack Dorsey’s Twitter account was hacked on Friday afternoon by a group that calls itself the Chuckle Squad. Twitter’s communications team issued a statement via Twitter.

The hackers tweeted racial slurs from Dorsey’s account. Some offensive tweets were up for about 10 minutes, though not long after the hack began, those tweets were being deleted. The hackers also plugged a Discord serve, asking people to join it. (The server invitation link tweeted out by the hackers no longer works.) “Both the server and the server owner were permanently removed from Discord within minutes of this being reported to us,” a Discord representative told The Verge.

“Encouraging any kind of hacking is in direct violation of our Terms of Service,” the representative said. “We will continue to monitor and investigate this incident.”

The tweets appear to come from Cloudhopper, a company that Twitter previously acquired to help with its SMS service. If you text 404-04 from the phone number linked to your Twitter account, that text will post to Twitter. The source in the tweet will be given as “Cloudhopper."