Twitter has told employees that all of the company's office buildings will be temporarily closed, effective immediately.
In a message seen by the BBC, workers were told that the offices would reopen on Monday 21 November.
It did not given 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."
Twitter did not immediately respond to a request for comment from the BBC.
This week Mr Musk told Twitter staff that they had to commit to working "long hours at high intensity" or else leave the company, according to reports.
In an email to staff, the firm's new owner said workers should agree to the pledge if they wanted to stay, the Washington Post reported.
Those who did not sign up by Thursday would be given three months' severance pay, Mr Musk said.
One Twitter worker who wished to remain anonymous told the BBC that they had resigned even though they had been prepared to take on the increased workload demanded by Mr Musk.
"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.
source> BBC.COM
