Per Reuters: The company notified employees that it will close its offices and cut badge access until Monday, according to two sources. Security officers have begun kicking employees out of the office on Thursday evening, one source said.

Twitter, which has lost many of its communication team members, did not respond to a request for comment.

The departures include many engineers responsible for fixing bugs and preventing service outages, raising questions about the stability of the platform amid the loss of employees.

On Thursday evening, the version of the Twitter app used by employees began slowing down, according to one source familiar with the matter, who estimated that the public version of Twitter was at risk of breaking during the night.

"If it does break, there is no one left to fix things in many areas," the person said, who declined to be named for fear of retribution.

Reports of Twitter outages rose sharply from less than 50 to about 350 reports on Thursday evening, according to website Downdetector, which tracks website and app outages.