The Trump administration reportedly told at least six senior FBI officials to retire, resign, or be fired by Monday.
The officials targeted were at the executive assistant director level or special agent in charge level and include those who oversee cyber, national security, and criminal investigations, CNN reported Thursday night.
A current FBI official told NBC News that the move would be "hugely disruptive."
The news came on the same day FBI director nominee Kash Patel was grilled by the Senate Judiciary Committee at a contentious confirmation hearing.
President Donald Trump accused his predecessor, former President Joe Biden, of weaponizing the Justice Department and FBI against his political enemies. The president has promised to overhaul the bureau.
Former FBI Director Christopher Wray resigned before Trump took office. Paul Abbate, who as the FBI's longtime deputy director was expected to replace Wray on an acting basis, retired from the bureau on Inauguration Day.
Former agent Tom Ferguson, an aide to Rep. Jim Jordan, R-Ohio, became a policy adviser at the bureau after Trump was sworn in.
The latest news of officials being told to leave has "drawn internal consternation," CNN reported, because the officials cited weren't involved in prosecutions of Trump regarding Jan. 6, 2021, or alleged mishandling of classified documents.
The outlet also reported that FBI Agents Association officials recently met with Patel to raise concerns that some agents may be targeted for termination unfairly.
CNN reported that FBI agents and supervisors can't choose the assignments to which they are assigned. It also said many FBI employees assigned to Trump cases were reluctant to proceed in their duties.
Patel on Thursday insisted to Democrats that he did not have an "enemies list" and that the bureau under his leadership would not seek retribution against the president's adversaries or launch investigations for political purposes.
"I have no interest, no desire, and will not, if confirmed, go backwards," Patel said at the confirmation. "There will be no politicization at the FBI. There will be no retributive actions taken."
The Associated Press contributed to this story.