Several top FBI executives promoted by former Director Christopher Wray were told Thursday to resign or retire and that they will be demoted or reassigned if they don’t leave, according to one current and three former bureau officials.

The purge of senior officials includes about a half-dozen “executive assistant directors,” who are some of the bureau’s top managers overseeing criminal, national security and cyber investigations. They are career civil servants, meaning they can’t be fired without cause.

A current FBI official told NBC News that the move would be “hugely disruptive,” while a former official who is talking to people at the FBI said there’s a lot of anger because the affected employees aren’t considered political figures in any way.