The Rockland Health Department was authorized by the state Wednesday to bar students without at least two doses of the MMR vaccine from attending school.

The county says they are contacting schools to prevent measles from further spreading.

There are 11 confirmed cases of the measles in the area and at least three more under investigation. Rockland County health officials are calling it a measles outbreak.

MORE: Measles alert issues in Weschester and Rockland counties

MORE: 7 cases of measles confirmed in Rockland County

On Thursday, officials sent home letters to parents of students at schools with confirmed cases to ask them to keep unvaccinated students home until at least Nov. 3.

If any additional cases of measles occur at a school, students without MMR vaccines will need to remain at home for an additional 21 days.

According to a news outlet geared towards the Hasidic Jewish community, two children who contracted the measles attend Visnitz Girls School in Monsey.

Free vaccinations will be held on Friday from 9:30 a.m. – 11:30 a.m. at the Pascack Community Center in Nanuet.

Officials say the outbreak started after five people returning from Israel came down with the disease.