According to international media reports, the departures come after billionaire Elon Musk’s $44 billion takeover of the company last week, followed by his firing of CEO Parag Agrawal, chief financial officer Ned Segal, and legal affairs and policy chief Vijaya Gadde, Reuters reported below citing sources.

Sarah Personette, who was chief customer officer and advertising executive, tweeted Tuesday, Nov. 1, that she resigned last week, adding to advertisers’ uncertainty about how the social media company will transform under Musk.

Chief People and Diversity Officer Dalana Brand announced in a LinkedIn post-Tuesday that she, too, resigned last week. Core Technologies general manager Nick Caldwell confirmed his departure on Twitter, changing his profile bio to “former Twitter executive” by Monday night.

Chief marketing officer Leslie Berland, Twitter’s head of product Jay Sullivan and its vice president of global sales Jean-Philippe Maheu have also left, a person with knowledge of the matter told Reuters. It wasn’t immediately clear if they were quitting or being asked to leave.

A coalition of more than 40 advocacy groups, including the NAACP and Free Press, on Tuesday, sent an open letter to Twitter’s top 20 advertisers, urging them to withdraw their ads if Musk approves of moderating content on the platform.

Read: Keep complaining, Twitter will charge $8 per month for blue tick: Musk

A series of sweeping changes the 51-year-old entrepreneur has implemented at Twitter, with the entire board, including CEO Parag Agrawal, let go last week.

The Washington Post has reported that Musk, whose account bio currently reads “Twitter Complaint Hotline Operator,” plans to fire some 75 percent of his company´s 7,500 employees.

Musk financed the massive deal through a mixture of his own wealth, money from other investment groups, and loans from banks which will have to be reimbursed.