Twitter has told employees that the company’s office buildings will be temporarily closed, with immediate effect.
In a message seen by the BBC, workers were told that the offices would reopen on Monday 21 November.
It did not give a reason for the move.
The announcement comes amid reports that large numbers of staff were quitting after new owner Elon Musk called on them to sign up for “long hours at high intensity” or leave.
The message went on to say: “Please continue to comply with company policy by refraining from discussing confidential company information on social media, with the press or elsewhere.”
There are signs that large numbers of workers have resigned because they have not accepted Mr Musk’s new terms.
One former Twitter employee, who wished to remain anonymous, told the BBC: “I think when the dust clears today, there’s probably going to be less than 2,000 people left.”
They claimed everyone in their team had been sacked.
“The manager of that team, his manager was terminated. And then that manager’s manager was terminated. The person above that was one of the execs terminated on the first day. So there’s nobody left in that chain of command.”
Another person said they had resigned even though they had been prepared to work long hours.
“I didn’t want to work for someone who threatened us over email multiple times about only ‘exceptional tweeps should work here’ when I was already working 60-70 hours weekly,” they said.