Hundreds of Twitter Inc employees are estimated to have decided to quit the beleaguered social media company following a Thursday deadline from new owner Elon Musk that staffers sign up for “long hours at high intensity,” or leave.

The departures highlight the reluctance of some of Twitter’s 3,000 or so employees to remain at a company where Musk earlier fired half of the workforce including top management, and is ruthlessly changing the culture to emphasize long hours and an intense pace, a Reuters report on Friday stated.

Musk took to Twitter late on Thursday and said that he was not worried about resignations as “the best people are staying.”

The billionaire owner also added: “We just hit another all time high in Twitter usage…,” without elaborating.

Musk met some top employees on Thursday to try to convince them to stay, said one current employee and a recently departed employee who is in touch with Twitter colleagues.

The company also notified employees that it will close its offices and cut badge access until Monday, according to two sources. Security officers began kicking some employees out of one office on Thursday evening, one source said.

Over 110 Twitter employees across at least four continents had announced their decision to leave in public Twitter posts reviewed by Reuters, though each resignation could not be independently verified. About 15 employees, many in ad sales, posted their intention to stay at the company.

In Twitter’s internal chat tool, over 500 employees wrote farewell messages on Thursday, a source familiar with the notes said.

A poll on the workplace app Blind, which verifies employees through their work email addresses and allows them to share information anonymously, showed 42 percent of 180 respondents opting for “Taking exit option, I’m free!”

A quarter said they had chosen to stay “reluctantly,” and only seven percent of the poll participants said they “clicked yes to stay, I’m hardcore”.

The exact number of employees intending to leave the company could not be immediately established. Twitter 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.