The Education Department placed a number of employees across its offices on administrative leave on Friday, part of a wave of what staff members and union representatives say are dozens of suspensions at the agency in the Trump administration’s purge of diversity efforts.

In letters obtained by The New York Times, the department notified affected employees that they would lose access to their email accounts, but would continue to receive pay for an indefinite period.

The department cited guidance from the Office of Personnel Management, which had directed agencies to submit plans for shedding staff associated with diversity, equity and inclusion efforts by the end of the day on Friday.

Brittany Holder, a spokeswoman for the American Federation of Government Employees, said the union estimated that at least 50 department employees had been suspended.

The range of people affected led several of those who had been placed on leave to conclude that they had been ensnared in a governmentwide effort to stamp out diversity initiatives, despite what they described as little more than superficial contact with mentors offering general coaching on workplace inclusivity.

The move was an early indication that Trump officials had begun looking to root out any D.E.I. efforts believed to be conducted “in disguise” after they had already moved to shutter offices explicitly focused on those efforts earlier in the week. It came as dozens of agencies raced to comply with an order issued by President Trump on his first day in office directing them to dismantle diversity offices and remove staff affiliated with them.

But according to interviews with those placed on leave and people familiar with the notifications, the department appeared to have cast a wide net, suspending people whose job titles and official duties had no connection to D.E.I., and whose only apparent exposure to D.E.I. initiatives came in the form of trainings encouraged by their managers. One of the training workshops that employees speculated may have led to their being flagged took place more than nine years ago.

It was not immediately clear what criteria the department used to identify those placed on leave, or which of those employees’ activities might fall under the broad order issued by Mr. Trump to roll back D.E.I. initiatives across the federal government. The Office of Personnel Management memo laying out the purge of diversity programs last month called on employees to report any efforts to “disguise these programs by using coded or imprecise language.”

A spokesman for the department did not respond to requests for comment.

Subodh Chandra, a civil rights lawyer who is representing one of the staff members placed on leave in the Education Department’s Office for Civil Rights, said his client was “utterly baffled” by the move. The staff member, a West Point graduate and an army veteran, was appointed to the employment, engagement and diversity and inclusion council formed under Mr. Trump’s previous administration by his political appointees, Kimberly Richey and Kenneth Marcus. A former prosecutor, he has received “perfect” ratings in the last three evaluations, Mr. Chandra said, in his role overseeing a two-state regional office.

The committee continued under President Joseph R. Biden Jr., but it has not met since December, Mr. Chandra said, and certainly not since Mr. Trump took office.

“My client served his country with distinction in the U.S. Army during and after 9/11,” Mr. Chandra said. “He happens to be a white male, although that shouldn’t make any difference, whether he or anyone else is a victim of a McCarthyist witch hunt. He should not be a victim of retaliation for opposing discrimination against anyone. And I hope the administration will stop misguided persecution of those serving our country faithfully. We are contemplating all of our legal remedies.”

Another staff member, who spoke on the condition of anonymity because of their tenuous position, said that diversity trainings were seen as routine around the department, with one two-day session having drawn around 300 people over several years.

Several staff members said that Denise L. Carter, who was named acting education secretary until Mr. Trump’s nominee to lead the department is confirmed, had urged colleagues to attend sessions, offering them at no cost to participants as recently as last year.

The recipients of the letters giving notice of suspensions included staff members who worked in the department’s Federal Student Aid office and others in the civil rights office. The department also notified all employees in the civil rights office who had joined recently and were still in a probationary period that their positions would be reviewed to determine their necessity.

The letters told employees that the decision to place them on leave was “not being done for any disciplinary purpose,” and was “pursuant to the president’s executive order.” But they did not specify how long the leave would last, or why those employees had been identified for suspension.

Through its first two weeks, the Trump administration has repeatedly said it would temporarily pause certain programs and sideline some federal workers while it conducts more comprehensive reviews that could inform staff reductions and bureaucratic changes. But it has done so haphazardly, leading to unintended disruptions and stoking anxiety among many federal workers.