WASHINGTON (AA) – New York City has put roughly 9,000 employees on unpaid leave after they refused to comply with the city’s COVID-19 vaccine mandate, Mayor Bill de Blasio announced on Monday.

That figure represents less than 6% of New York City’s municipal work force, de Blasio said at a press conference. Some 12,000 other unvaccinated employees have applied for a medical or religious exemption and are expected to receive a final determination “in the coming days,” the mayor said.

They can remain on the job while their cases are evaluated.

About 91% of the city’s workforce has complied with the mandate, which went into effect on Monday. Employees had to receive at least one dose of a COVID-19 vaccine by last Friday at 5 pm to receive a $500 bonus, but over 3,500 got their jabs over the weekend.

“Anyone who hasn’t so far, there’s still a chance to fix it: come in, get vaccinated, come back to work, because we need everyone to do their job, and we need everyone to be safe,” de Blasio said. “We know more people will get vaccinated.”

A small minority of New York City’s workforce had ardently and vocally opposed the mandate, and the union that represents the city’s firefighters had raised the alarm that it could jeopardize public safety in the US’s largest city.

Still, de Blasio said there have been no firehouses that have closed, and response times remain “normal” for firefighters, EMS workers, and police.

He warned, however, that it appears an unusually high number of workers are “claiming to be sick who are not” amid rumors of a coordinate “sick out,” threatening potential legal action.

“It’s not acceptable,” de Blasio said. “The thing to do is to do the right thing: come to work, protect people as you took an oath to do. And look, this is something that we don’t tolerate. In the end, when people do this kind of thing there are consequences.”