Hundreds of anti-vaccine protesters marched through Brooklyn and Manhattan on Monday, chanting into loudspeakers and at one point tearing down a coronavirus testing site as they expressed opposition to New York City’s vaccine mandate for school employees.

New York City public school employees were required to receive at least one shot of a coronavirus vaccine by Monday morning when schools opened for class, or face unpaid leave, in accordance with a mandate that Mayor Bill de Blasio issued in August. As of Monday, 95 percent of all full-time employees had received at least one dose, the mayor said.

“One of the most important actions we took was the mandate for our schools,” the mayor told reporters. “Our parents needed to know their kids would be safe. They entrust us with their children.” Teachers who comply with the vaccine mandate will be welcomed back from unpaid leave, the chancellor for the city’s schools, Meisha Porter, said.