(Reuters) - U.S. Food and Drug Administration employees reviewing Elon Musk's brain implant company Neuralink were fired over the weekend as part of a broader purge of the federal workforce, according to two sources with knowledge of the matter.

The cuts included about 20 people in the FDA's office of neurological and physical medicine devices, several of whom worked on Neuralink, according to the two sources, who asked not to be identified because of fear of professional repercussions. That division includes reviewers overseeing clinical-trial applications by Neuralink and other companies making so-called brain-computer interface devices, the sources said.

Both sources said they did not believe the employees were specifically targeted because of their work on Neuralink's applications.

The loss of roughly 20 employees will hamper the agency's ability to quickly and safely process medical device applications of all sorts, including Neuralink's, according to the sources and outside experts.

"It's intimidating to the FDA professionals who are overseeing Neuralink's trial," said Victor Krauthamer, a former FDA official for three decades, including a stint as acting director of the office that reviews human-trial requests for brain implants.

"We should be worried about the whole trial, and the protection of the people in the trial."

The FDA, White House and Musk did not immediately respond to comment requests. Trump has said that Musk will excuse himself from any conflicts of interest between his various business interests and his efforts to cut costs for the federal government.

Similar to other government agencies, the cuts affected scientists reviewing medical device applications who were probationary, one of the sources said. Probationary employees typically have less than one year or in some cases less than two years of service and have fewer legal protections.

Neuralink is currently testing its device, which allows paralyzed people to use digital devices solely via thought, in a small number of disabled patients. The company is also working on an implant aimed at restoring vision. Last year, the FDA gave that device a designation aimed at speeding up development and federal review, the company has said.

After spending more than $250 million to get President Donald Trump re-elected, Musk has been leading a sweeping effort to cut government spending, including at agencies that regulate his companies, such as Tesla and SpaceX.

The dismissal letters sent to the FDA reviewers cited performance reasons, even though the employees had no issues on their prior performance, and had received top-notch rankings several weeks ago, according to the two sources familiar with the matter. The supervisors of the cut employees weren't consulted before the mass layoffs and found out from their employees, the sources said.

(This story has been corrected to say $250 million, not $250 billion, in paragraph 10)