Police and school officials are investigating after three swastikas were found at Montclair High School on Tuesday, Dec. 10.

The swastikas were discovered on two desks in a classroom in the high school's main building, Principal Anthony Grosso said in a letter to families Wednesday morning. One desk was found to have two swastikas on it, and a third swastika was found on another desk.

The teacher assigned to the classroom reported the issue to school administration, Grosso said. The desks were removed from the classroom so school staff remove the markings.

"Behavior such as this will not be tolerated at Montclair High School and those found responsible for these actions will be subject to disciplinary action aligned with the Student Code of Conduct," Grosso wrote.

It is the second incident in just over a month that a swastika was found at the school. On Nov. 5, the school sent a letter to parents after a swastika and the word "cake" were found written in pencil on a table in the high school cafeteria. The incident was referred to the Montclair Police Department's Juvenile Aid Bureau for investigation.

Tuesday's incident at Montclair High School occurred on the same day that a shooting took place in Jersey City at a kosher grocery. A police officer and three people were killed. Media reports and statements from city officials indicate that the store appeared to have been intentionally targeted by the shooters.

"This display of anti-Semitism is an example of why the ongoing work of fostering an inclusive and accepting environment is vital to the students in our community.  We ask that you partner with Montclair High School, especially during this holiday season, and have a conversation with your children about how this symbol of hate impacts the many members of our school and community," Grosso wrote.

The school is working with the Montclair Police Department to investigate the incident, Grosso said. The school will also be working with its community partners, including the Anti-Defamation League, on education in light of the incident, Grosso said.