SAN FRANCISCO — Elon Musk has started cleaning house at Twitter with the firings of at least four top executives Thursday, said two people with knowledge of the situation, as the billionaire closes his $44 billion takeover of the social media company.

The Twitter executives who were fired include Parag Agrawal, Twitter’s CEO, Ned Segal, the chief financial officer, Vijaya Gadde, the top legal and policy executive, and Sean Edgett, the general counsel, said the people, who declined to be identified because they were not authorized to speak publicly.

At least one of the executives who was fired was escorted out of Twitter’s office, they said.

Musk faces a deadline of Friday to complete his deal to buy Twitter. It was unclear if he had closed the acquisition by the time the executives were fired. He arrived at the company’s headquarters in San Francisco on Wednesday and has been meeting with engineers and advertising executives.

The billionaire, 51, has promised to transform Twitter by taking it private, loosening the service’s content moderation rules, making its algorithm more transparent and nurturing subscription businesses, as well as laying off employees. Musk at one point tried to back out of the deal but recommitted to it this month as he faced legal challenges for trying to withdraw.

Musk, Agrawal, Segal, Gadde, Edgett and a Twitter spokesperson did not immediately respond to requests for comment.

Agrawal, who was appointed Twitter’s CEO last year, had clashed with Musk publicly and privately in recent months about the takeover. Musk had also singled out Gadde, criticizing her for her role in content moderation decisions at the company.

This article originally appeared in The New York Times.