Dozens of Twitter employees were fired overnight on Wednesday, people familiar with the matter told Insider.
The firings, of mostly engineers, came as a surprise inside Twitter, the people said.
Thousands of Twitter staff have been laid off, resigned, or fired since Musk took over.
Elon Musk fired several dozen Twitter employees overnight on Wednesday, most of whom were engineers, two people familiar with the company's actions told Insider.
The firings came as a surprise inside Twitter, the people said. Musk said in an all-hands meeting earlier this week that there would be no more layoffs at the company.
The employees fired overnight on Wednesday were informed they were being laid off for performance reasons, and were given one month of severance, one of the people said.
The termination process was similar to that experienced by previously laid-off employees, the two people said: Access to work tools and computers were cut off, and a notice of termination was sent to affected employees' personal email accounts.
Thousands of Twitter employees have already been laid off, resigned, or fired by Musk, leaving critical workers stretched thin. Twitter teams are already so short-handed that many employees have had to work on Thanksgiving, the people said.
The firings are thought to be, at least in part, a result of Musk's new policy requiring Twitter engineers and other staff working on code or technical projects to update him every week about what they worked on, what they hoped to complete, and specific lines of code they wrote, as Insider previously reported. While these updates are typically expected on Fridays, this week, they were due on Wednesday because of the Thanksgiving holiday.
Twitter recruiters have reportedly tapped external engineers to work for the company under Musk, and Musk has even hired a hoaxer who fooled the press into thinking he'd just been laid off from Twitter. These developments had led staff to believe that Musk had kicked his habit of sudden firings, one of the people said.
A representative for Musk didn't immediately respond to Insider's request for comment.