More than 2,000 New York City firefighters took medical leave this past week as the deadline for showing proof of full vaccination has passed and city workers who failed to comply with the mandate now face being placed on unpaid leave.

New York City Fire Department (NYFD) Deputy Commissioner Frank Dwyer called the number of firefighter who have called out sick “very unusual,” according to an NBC News report.

NYFD Commissioner Daniel A. Nigro lambasted workers who are taking part in a “sickout” to protest the mandate.

“Irresponsible bogus sick leave by some of our members is creating a danger for New Yorkers and their fellow Firefighters,” Nigro said, according to NBC. “They need to return to work or risk the consequences of their actions.”

Nigro also shot down reports that the lack of working firefighters has caused firehouses to be closed down, saying the department “has not closed any firehouses.”