The F.B.I. is forcing out at least two agents, including a former acting head of the bureau, as the director, Kash Patel, continues a purge at the nation’s premier law enforcement agency, according to several people familiar with the matter.

Brian Driscoll, who briefly served as the acting director in the early days of the Trump administration, was among those being told to leave by Friday, according to the people, who spoke on the condition of anonymity to describe personnel decisions that have not yet been made public.

The reason for Mr. Driscoll’s ouster was not entirely clear, but his removal will most likely deal another blow to the morale of the agency, which has faced intense scrutiny after conducting investigations that President Trump’s supporters have denounced.

Mr. Driscoll had become an unlikely champion of the bureau, accidentally catapulted to the director’s chair after Mr. Trump was inaugurated. His tumultuous tenure included fighting off what was seen as a possible purge of F.B.I. agents who had worked on the investigation into the Capitol attack.

Another agent being pushed out is Walter Giardina, who was involved in a number of investigations related to Mr. Trump, including a case that sent the trade adviser Peter Navarro to prison. The Republican chairman of the Senate Judiciary Committee, Charles E. Grassley of Iowa, has criticized Mr. Giardina for what whistle-blowers have claimed is anti-Trump bias.

It was not immediately clear if the administration intended to remove other F.B.I. employees who had been targeted by Trump supporters.