(JTA) — The New York City Department of Health has threatened to fine or even close yeshivas in the Williamsburg neighborhood of Brooklyn if students who are not vaccinated against measles are allowed to attend classes.

The crack-down comes more than a week before the Passover holiday, when large and extended Orthodox families gather and when synagogues are more full than usual.

There have been 285 reported cases of measles in Brooklyn’s Orthodox Jewish community since October, 246 of which are children, CBS New York reported, citing the health department.

CBS reported that the “vast majority” of children in the largely haredi Orthodox community of Williamsburg are vaccinated, but that it continues to spread due to how tightknit the community is. The community’s rabbis have called on the haredi public to get vaccinated, according to the report.

The health department in December ordered yeshivas and day care centers in specific Brooklyn zip codes, populated largely with haredi Orthodox, to exclude all non-vaccinated students until the end of the current measles outbreak. A Williamsburg yeshiva that fell out of compliance in January is connected to more than 40 measles cases, ABC7 New York reported.

On Friday, a New York state judge lifted the state of emergency imposed by Rockland County that would have barred minors not vaccinated against the measles from public places.

The Brooklyn outbreak has been tied to an unvaccinated child who contracted the disease during a trip to Israel, the Washington Post reported.

 Photo credit: Hannah Smith/KOMU/Flickr